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  • 201.
    Adenfelt, Maria
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Lagerström, K.
    Organizational rejuvenation for knowledge exploitation: Exploring corporate entrepreneurship in an MNE2006Inngår i: Journal of International Entrepreneurship, ISSN 1570-7385, E-ISSN 1573-7349, Vol. 4, nr 2-3, s. 83-98Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this paper is to study how organizational rejuvenation is used to increase and support knowledge exploitation in multinational enterprises. Using case-study data to explore the theoretical arguments, interesting findings emerge. The main finding is that entrepreneurial activities in IT industry enable organizational rejuvenation with repercussions beyond the focal function. Other findings relate to how corporate entrepreneurship activities provide possibilities for continuous knowledge exploitation within the MNE and how entrepreneurial groups inside MNEs form the foundation from which the organizational rejuvenation originates. Finally, the form of organizational rejuvenation studied embraced both structural and behavioral changes.

  • 202.
    ADER, MARIA
    et al.
    KTH, Skolan för industriell teknik och management (ITM).
    AXELSSON, DAVID
    KTH, Skolan för industriell teknik och management (ITM).
    Drones in arctic environments2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This is a master thesis by Maria Ader and David Axelsson, students at the Master of Science in Engineering degree program in Design and Product Realization at KTH, within the master program Integrated Product Design. The thesis work will benefit ÅF and the EU project ɪɴᴛᴇʀᴀᴄᴛ.

    The ɪɴᴛᴇʀᴀᴄᴛ project is part of the EU’s effort to forward climate research, and aims to “coordinate and harmonize research and monitoring efforts that will greatly contribute to our knowledge and understanding of changes occurring in the arctic environment.” One out of 12 subprojects within ɪɴᴛᴇʀᴀᴄᴛ aims to “increase awareness of drone technology and sensors among researchers and research station managers while making industry aware of innovative potential uses requiring drone and sensor development.”

    A drone is an unmanned aerial system/vehicle (UAS/UAV), i.e. an airborne vehicle without a human pilot aboard. This master thesis examines the need of drones at the ɪɴᴛᴇʀᴀᴄᴛ research stations and how arctic climates affect drone technology and the ergonomics of piloting a drone. The thesis also provides an overview of the current state of the drone market and the laws and regulations that affect the use of drones.

    A survey was distributed within ɪɴᴛᴇʀᴀᴄᴛ to map the researchers’ need of, and attitudes towards, drones, followed by exhaustive interviews with researchers and other key figures. Field testing at Tarfala Research Station provided complementing data.

    The primary insight from the study was that the researchers’ need, as well as the tasks and methods that they employ, vary greatly. Another insight was that many researchers want to use drones primarily as a sensor platform to collect data from large areas in a short time span.

    A situation-based drone recommendation and a concept proposal for a simple water sampling solution were made based on the results of the study

  • 203.
    Adineh, Morteza
    et al.
    Shahid Bahonar Univ Kerman, Coll Engn, Dept Mat Engn & Met, Kerman 7618868366, Iran..
    Doostmohammadi, Hamid
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap. Shahid Bahonar Univ Kerman, Coll Engn, Dept Mat Engn & Met, Kerman 7618868366, Iran..
    Microstructure, mechanical properties and machinability of Cu-Zn-Mg and Cu-Zn-Sb brass alloys2019Inngår i: Materials Science and Technology, ISSN 0267-0836, E-ISSN 1743-2847, Vol. 35, nr 12, s. 1504-1514Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lead-free alloys have attracted great attentions recently due to the toxic nature of lead for the human body. In this study, low amounts of Mg and Sb were added to the Cu65-Zn35 brass and microstructure, mechanical properties and machinability of samples were compared to Cu65-Zn35 brass. Both Mg and Sb led to the promotion of beta ' phase as well as the formation of new ternary copper rich intermetallic particles. It was found that these particles had a significant role in the reduction of the ultimate tensile strength, toughness, work hardening and elongation while increasing the hardness of samples. Results of machinability evaluation of samples showed that the cutting forces were decreased significantly and morphology of chips were improved compared to Cu65-Zn35 brass sample.

  • 204. Adit Maark, T.
    et al.
    Hussain, T.
    Ahuja, Rajeev
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik.
    Structural, electronic and thermodynamic properties of Al- and Si-doped α-, γ-, and β-MgH2: Density functional and hybrid density functional calculations2012Inngår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 37, nr 11, s. 9112-9122Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work, we present a detailed study of Al- and Si-doped α-, γ-, and β-MgH 2 phases using the gradient corrected density functional GGA-PBE and the hybrid Hartree-Fock density functionals PBE0 and HSE06 within the framework of generalized Kohn-Sham density functional theory (DFT) using a plane-wave basis set. We investigate the structural, electronic, and thermodynamical properties of these compounds with regard to their hydrogen storage effectiveness. PBE0 and HSE06 predict cell parameters and bond lengths that are in good agreement with the GGA-PBE calculations and previously known experimental results. As expected smaller band gaps (E gs) are predicted by GGA-PBE for the pure magnesium hydride phases. PBE0 overcomes the deficiencies of DFT in treating these materials better than HSE06 and yields E gs that compare even better with previous GW calculations. Both the hybrid functionals increase the E gs of the Al-doped magnesium hydrides by much less magnitudes than of the Si-doped phases. This difference is interpreted in terms of charge density distributions. Best H 2 adsorption energies (ΔH ads) are computed by HSE06 while GGA-PBE significantly overestimates them. Si-doped α- and β-MgH 2 exhibited the least negative ΔH ads in close proximity to the H 2 binding energy range of -0.21 to -0.41 eV ideal for practical H 2 storage transportation applications.

  • 205. Adlercreutz, Ludvig
    et al.
    Cronhjort, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Andersen, J.
    Ogink, R.
    Optimizing the Natural Gas Engine for CO2 reduction2016Inngår i: SAE Technical Papers, SAE International , 2016, Vol. 2016-April, nr AprilKonferansepaper (Fagfellevurdert)
    Abstract [en]

    With alternative fuels having moved more into market in light of their reduction of emissions of CO2 and other air pollutants, the spark ignited internal combustion engine design has only been affected to small extent. The development of combustion engines running on natural gas or Biogas have been focused to maintain driveability on gasoline, creating a multi fuel platform which does not fully utilise the alternative fuels' potential. However, optimising these concepts on a fundamental level for gas operation shows a great potential to increase the level of utilisation and effectiveness of the engine and thereby meeting the emissions legislation. The project described in this paper has focused on optimising a combustion concept for CNG combustion on a single cylinder research engine. The ICE's efficiency at full load and the fuels characteristics, including its knock resistance, is of primary interest - together with part load performance and overall fuel consumption. In the process of increasing the efficiency of the engine the following areas have been of primary interest, increased compression ratio, thermal load at high cylinder pressure and the use of EGR to further increase efficiency. The overall goal in the project was to reduce the CO2-emissions while maintaining the performance and characteristics of the engine. The ambition is to reduce specific tail-pipe CO2-emissions in g/kWh by 50% compared to a modern gasoline engine. The goal was close to being reached at 45% reduction at full load and 25-34% on part load. This was done by theoretically downsizing the engine and increasing the specific performance of the engine.

  • 206. Adlercreutz, Ludvig
    et al.
    Cronhjort, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Stenlåås, Ola
    Particle Emission Measurements in a SI CNG EngineUsing Oils with Controlled Ash Content2019Inngår i: SAE Technical Papers, 2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Clean combustion is one of the inherent benefits of using a high methane content fuel, natural gas or biogas. A single carbon atom in the fuel molecule results, to a large extent, in particle-free combustion. This is due to the high energy required for binding multiple carbon atoms together during the combustion process, required to form soot particles. When scaling up this process and applying it in the internal combustion engine, the resulting emissions from the engine have not been observed to be as particle free as the theory on methane combustion indicates. These particles stem from the combustion of engine oil and its ash content. One common practice has been to lower the ash content to regulate the particulate emissions, as was done for diesel engines. For a gas engine, this approach has been difficult to apply, as the piston and valvetrain lubrication becomes insufficient. However, the low particle emissions from the combustion of CNG does allow for an investigation of particle contribution from engine oil ash content with only a minor particle contribution from the fuel itself. The hypothesis for this study is that there is a relationship between the engine oil ash content and the particulate emissions from a CNG engine. The investigation was conducted for several operating points with varying engine speeds and load on a single cylinder engine. The single cylinder approach was chosen to reduce sources of engine oil intrusion in the combustion chamber. The obtained results were not in line with the hypothesis, the particle emissions from the lower ash content oil did not decrease in number but the size of the particles did. The results also showed a spiking behavior in the particulate emissions, originating from the lubrication oil consumption past the piston rings. Mass flow through the engine proved to affect the particle size distribution as well as the total number of particles for all levels of oil ash content.

  • 207. Adlercreutz, Ludvig
    et al.
    Cronhjort, Andreas
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Stenlåås, Ola
    Variation in Squish Length and Swirl to Reach Higher Levels of EGRin a CNG Engine2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Gaseous methane fuel for internal combustion engineshave proved to be a competitive source of propulsionenergy for heavy duty truck engines. Using biogascan even reduce the carbon footprint of the truck to near-zerolevels, creating fully environmentally friendly transport. Gasengines have already been on the market and proved to be apopular alternative for buses and waste transport. However,for long haulage these gas engines have not been on par withthe equivalent diesel engines. To improve the power and efficiencyof EURO VI gas engines running stoichiometrically, adirect way forward is adding more boost pressure and sparkadvance in combination with more EGR to mitigate knock.Using in-cylinder turbulence to achieve higher mixing rate,the fuel can still be combusted efficiently despite the increasedfraction of inert gases. In this paper, previous findings onin-cylinder air flows for diesel engine simulations are investigatedfor the applicability on to stoichiometric gas combustion.Two key parameters were identified, swirl and squish.By varying the levels of swirl with different squish lengths inthe piston design, the in-cylinder flow motion is altered toinvestigate its effect on stoichiometric gas combustion. Thetesting was performed on a single cylinder research engineoperated in the equivalent multi cylinder engine operatingpoints. The results show that previous modelling findings areverified on the pre-mixed gas combustion studied. By choosingswirl and squish for the design of the gas engine, it is possibleto increase the combustion speed and thus the fraction of EGRin the combustion charge, without the latter having a negativeimpact on the combustion.

  • 208.
    Admasu, Alemshet Ayele
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Solar PV based rural electrification in Rema rural village2011Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Energy is a basic need for the overall growth and improvements of people’s living standard.But around 2 to 3 billion people in the world have no access to electric lighting. Like otherdeveloping countries the rural electrification in Ethiopia is very low and government takessome actions to promote the investment in these areas but due to economic constraints andlow level of technological advancement the growth is very low.This study focuses on solar PV based rural electrification, its impact on environment andsocio-economic development in Rema village. Three cases studies: typical households,small scale business center and public services are considered for systematic study.Interviews from villagers, existing energy system, literature data and HOMER software areused to calculate energy demand and cost of electrification. A comparison between theresults is carried out.According to the village survey the existing PV home system has a positive impact on a socioeconomic development of the village of Rema. Solar PV electricity can be used in generatingincomes. It is also used for climate mitigation by curbing CO2 emission and can be used forclimate adaptation by reducing the deforestation and facilitate carbon sequestration. PVbased electrification of health center and schools have played a vital role in improving thequality of services. The presence of refrigerator helped to have vaccines and medicines4preserved for different types of killer diseases. The teaching-learning process of schoolsimproved due the presence of electricity. The solar powered water supply in near areasreduced the time required for fetching water and made girls to focus on their education.Most villagers has positive attitude towards the technology but unsatisfied with the currentsystem size. The high level of technical skills required for maintenance and the small numberof solar technicians’ available in the village is also a problem reported in the village. HOMERsoftware is used to model the existing energy system and the required energy demandbefore PV based rural electrification and after PV based rural electrification. A new model isdeveloped depending on the villagers demand. . Modeling result shows that 3 kWP and 12kWP were found to be enough to fulfill the demand in clinics and schools with an initialinvestment of 18576 and 80704US$, respectively and a PV size of 165 Wp, 250 Wp and 350Wp is required for households with agriculture only, mixed and small scale business income,respectively. This led a requirement of initial capital of US$ 654, 1848 and 2339,respectively. However, these initial investments are unaffordable for most of the villagers.PV systems required for households with agriculture only, has lower investment per Wattthan others, while investment per Watt for small scale business has lower than householdswith mixed type. Therefore, the battery size plays an important role in the investment,operation and maintenance costs.The two main problems associated with solar PV in rural electrification are financial capabilityand technical problems. These problems can be curbed by loan arrangement and trainingthe villagers. But to make sustainable it must be used for income generating activities.

  • 209.
    Adnan, Al-Khalaf
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Oskar, Gustafsson
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Are hedge funds of benefit for institutional investors in a low interest-rate environment?2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 210.
    Adnot, Thibault
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Project Management within start-ups: Literary review and case studies in Stockholm, Sweden2012Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    This paper describes the way start-ups use Project Management, what their needs in this field are, and what tools they use to support it. In the first part of this paper, a comprehensive literature review is performed, divided into three main parts. First, Project Management in general is studied; second its benefits to SMEs are pinpointed; and finally its application to startups are reviewed. The second part of this paper is based on three case studies of start-ups in the Stockholm-region. Five representatives of these start-ups were interviewed, and the results of these face-to-face conversations are first exposed and then discussed by the author.

    In the end, this paper shows the traditional phase-based approach to Project Management does not suit start-ups. Instead, a more agile and iterative method is put forward, such as SCRUM. It is argued that such strategy should be kept by start-ups when growing and tapping other markets outside Sweden, although it is recognized that Project Management should become more formal than the general “on the go” approach witnessed in the three start-ups.

  • 211.
    Adolfi, Sofia
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Slag inclusion formation during solidification of steel alloys and in cast iron2007Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis explores the formation of segregation and inclusions during solidification of steel and cast iron. A better understanding of the formation mechanism should result in decreasing fraction of defects during solidification of ingot and strand material.

    Density driven macrosegregation was studied both experimentally and theoretically to see the effect of channel segregation on the total segregation. Formation of these pencil-like segregations is due to natural convection in the solidifying metal caused by liquid enrichment of elements with lower density compared to the bulk. It is suggested to change the composition to compensate for this density difference.

    Inclusion precipitation can be finite by limitations in segregation. Saturated liquid is found in the last solidified areas, often between dendrites. Here the enrichment of the liquid is possible due to microsegregation. Meanwhile crystals form and solidify the elements with low solubility in the solid is pushed out in the remaining liquid. Soon the liquid is saturated to the level where spontaneous formation of inclusions occurs. Microstructure studies by aid of SEM and micro-probe measurements are analysed to find at what point during solidification process the inclusions start to form. In steel making this formation has a detrimental effect on the mechanical properties in contrary to the production of nodular cast iron where the inclusions have a beneficial effect on the graphite formation.

    Inoculation of cast iron aims at reaching higher number density of graphite nodules, nodule morphology modification and control of nodule distribution during solidification. Late precipitation of nucleation sites has shown to have a positive impact on preventing chill. To find the most potent inoculation agent different additives were tested. Special effort has been made to analyse the effect of oxides and sulphides as nucleation sites.

  • 212.
    Adolfi, Sofia
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Mori, Kenji
    Fredriksson, Hasse
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    MnS precipitation during solidification in presence of oxide nuclei2007Konferansepaper (Annet vitenskapelig)
  • 213.
    Adolfsson, Johan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Thalén, David
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Utveckling av barnvagn2008Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    After contacting the company Elite Group Sverige AB, who sells strollers under the brand Crescent Baby, it was determined that the project group were to develop a three wheeled stroller which was going to be Crescents first own developed stroller. Only the frame of the stroller was considered within the demarcation of this project however care was taken to the placement of the carry-cot and the wheels etc. Crescent Baby wished for the frame would be smaller than the competitor Urban Jungle, that the frame would have at least three unique selling points and that the number of unique parts was to be minimized. The work began with information seeking regarding strollers, competitors, independent tests, European standards and consumer interviews. After that a number of concepts were developed and past to Crescent. From these concepts the one that was to be called Stealth was chosen. Stealth was further developed and CAD-files, pictures and blueprints were made for the frame Stealth has a classic and well tested suspension but now applicable with a three wheeled stroller. The frame is made up by aluminum profiles and injection moulded plastic details which link the profiles together. The frame is dimensioned to be smaller than Urban Jungle and its form is inspired by bicycles. Stealth has as of today a number of unique selling points and the frame is smaller than the maximum measurements specified. The number of unique parts has also been kept at a minimum. To continue the development the specifications for manufacturing have to be more defined, and the parts not treated in this thesis has to be developed.

  • 214.
    Adolphe, Cyril
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Commissioning the Heating and Cooling Systems on an FPSO (Floating Production Storage and Offloading facility)2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The project under discussion is the FPSO Ichthys. The FPSO is a ship comprising the offshore production facility for an oil&gas field, financed by INPEX/Total. An oil platform extracts the product received via the flexible risers and separates it into gas and condensate. The condensate is transferred to the FPSO, which processes it, and separates it between natural gas and oil. The oil is stored in the FPSO and then exported via a tanker. The gas is transferred via a pipeline.

    An FPSO is a complex installation in many respects. It is a condensate treatment factory, installed on a 450-metre-long ship. It should have the capacity to store one week’s condensate production. The FPSO is self-sufficient in terms of energy production (electricity, heating and cooling). Owing to the proximity of the hazardous production area to the living quarters, strict safety regulations are applied. For instance, all equipment has to be designed with redundancy (2x50% or 3x33% for critical equipment); the heating and cooling systems are managed with the help of emergency logic diagrams. These enable vital functions to be maintained even in cases of extreme failure.

    Despite its complexity, the FPSO has to be constructed within a short period of time. However, safety issues are important, and maintenance of defective equipment is expensive since the ship will be located 300km away from the coast. This is the reason why the constructor contracted Actemium, a part of VINCI Energies. Actemium commissions the FPSO. The commissioning mission has to prove that the systems function in accordance with the designs. Commissioning occurs right after the pre-commissioning (de-energized verifications). Commissioning is divided into three main activities: functional tests (which prove that individual pieces of equipment work in accordance with the designs); operational tests (which prove that all subsystems work in accordance with the designs of different modes); and piping and vessels pressurization (which prove that there is no leak).

    This master thesis describes the requirements of such projects and focuses on the operational tests. A description of the installation is detailed. Secondly, the subcontractor for the commissioning of the project, Actemium, and the method used for the commissioning are presented thereafter. Finally, the operational test procedures of the cooling and heating systems are examined in detail.

  • 215.
    Adson, Artur
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Matin, Timu
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Further Development of A Rescue Helmet2014Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The aim of this master's thesis was to further develop a helmet for search and rescue personnel, on request from AUK Protection, formerly known as Baering. This thesis succeeds the KTH MF2061 higher course project Baering Y1 - Product development of a new search and rescue helmet in collaboration with Baering in 2013. AUK Protection had identified a need for a purposely designed helmet through contact with members of Swedish Search and Rescue(SAR) and Swedish Sea Rescue Society(SSRS). There are approximately 2000 active SAR and SSRS members who use helmets designed for recreational activities, such as rafting and mountain climbing, for lack of a better alternative. The helmets are consequently modified to accommodate their specific needs. Essential rescue equipment, such as position lights and communication systems, are retrofit using fasteners, tape, straps and Velcro. User studies conducted in the MF2061 project indicated safety concerns with the aforementioned attachment methods. The retrofit components protrude from the helmet and often interfere with other rescue equipment, with the risk of entangling the user. The Y1 helmet concept produced in the MF2061 project was evaluated together members from SAR and SSRS, with focus on form and functionality. Different materials and manufacturing methods were researched and the manufacturability of the Y1 was analysed. It was ultimately decided to discontinue the development of the Y1 due to the feedback received. New concepts were generated with focus on anthropometric data, manufacturability, helmet safety standards and the ability to mount additional components. Different material combinations were investigated and evaluated using physical testing. Further development of the concepts involved clay sculpting and 3D CAD modelling. The final concept was chosen based on input from the users, AUK Protection and HOWL Design Studio. The R1 -Rescue One helmet is the result and supersedes currently available solutions for rescue applications. The essence of the R1 helmet is a modular mounting system that can be customized for use with third-party components. Prototypes were manufactured in the correct materials for further evaluation. Drop tests were performed according to PAS 028 standard validate the mechanical properties of the helmet.

  • 216.
    Adson, Artur
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Söderström, Amanda
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Laddstation för eldrivna taxibilar2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Det ställs allt högre krav på personbilar med avseende på bränsleförbrukning, CO2 emissioner och partikelutsläpp. Sedan den första miljöklassningen av bilar kom 1993 har kraven skärpts i omgångar och idag finns klassningarna 2000, 2005, EEV och El och Hybrid i Sverige. Allt fler biltillverkare väljer att lansera miljöbilar och i mars 2011 var 403359 miljöbilar registrerade i Sverige, en ökning med 35 procent mot föregående år. Arbetets mål var att utveckla ett koncept på en laddstation som gör det möjligt att ladda eldrivna taxibilar medan de står, alternativt kör sakta framåt, i en taxikö. Taxichaufförer intervjuades på två taxistationer i anknytning till Stockholms centralstation med syftet att kartlägga deras kö-vanor med avseende på kötid och hur frekvent taxikösystemen användes. Information inhämtades från Internet med sökmotorn Google och KTH Bibliotekets sökmotor för artiklar MetaLib. Vetenskapliga artiklar för grundläggande induktion, induktiv laddning, elbilar och fordon studerades och resulterade i en förenklad modell för beräkning av en induktiv koppling. Modellen uppskattade spoldimensioner, tillverkningskostnader och verkningsgrad hos trådlös energiöverföring. Slutkonceptet är en betongstolpe som monteras i marken vid sidan av körfilen. Energiöverföringen sker induktivt och utan fysisk kontakt mellan bil och laddstation. Med en spoldiameter på 700 mm är det möjligt att överföra energi med en verkningsgrad på över 50 procent vilket anses som hög verkningsgrad för trådlös energiöverföring. Maximala avståndet mellan bil och laddstation är 210 mm.

  • 217.
    ADUT, JONATHAN
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Organisation och ledning.
    Applying agile approaches in public construction and civil engineering projects: A study to identify opportunities for a more flexible projectmanagement process2016Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    I ett ständigt utvecklande affärsklimat, med nya projekt som tillkommer som aldrig förr, är  behovet av en effektiv projektledning inom alla områden nödvändig. Kärnan i projektledning är att noggrant planera, organisera, motivera och kontrollera resurser för att uppnå ett önskat resultat och för att uppfylla projektets mål. Traditionell projektledning ger en tydlig projektram som är skapad för att gälla för nästan alla typer av projekt. Att arbeta med projektfaser i traditionella bygg- och anläggningsprojekt har en tendens att vara alltför stelbent och tidskrävande för dagens dynamiska affärsmiljö.

    Projektledning handlar inte längre om att hantera de olika stegen som krävs för att slutföra projektet i tid, det handlar om att systematiskt involvera kunden, skapa ett disciplinerat sätt  att prioritera insatser och lösa kompromisser. Samtidigt kunna arbeta inom alla aspekter av projektet i multifunktionella team. Genom att studera agil projektledning möjliggörs just detta.

    Genom agila tillvägagångssätt kan projektets process vara en mer levande och en kontinuerligt uppdaterad process. Agil projektledning ger projektledare metoder, verktyg och framförallt tillvägagångssätt för att underlätta både projektledaren och projektbeställarens möjlighet att engagera sig på ett mer effektivt sätt, vilket möjliggör mer öppen kommunikation, bättre återkoppling och viljan att fullfölja ett gemensamt mål mot framgångsrik projektledning.

    Syftet med denna studie var att undersöka om projektledning inom bygg- och  nläggningsprojekt, som hittills mestadels har utförts på ett traditionellt sätt, skulle kunna dra nytta av att använda agila tillvägagångssätt. Genom att studera både traditionell projektledning och observera hur projekt genomförs på WSP Management, samt intervjua erfarna projektledare, identifierades att agila tillvägagångssätt kan utföras.

    Att kombinera den traditionella betydelsen av projektledning med agil projektledningsteori, dess värderingar och principer samt intervjuer med agila experter – blev det uppenbart att möjligheterna att använda och dra nytta av agila tillvägagångssätt inom bygg- och anläggningsprojekt är möjlig.

  • 218.
    af Burén, Claës
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Piska eller morot?: En studie av möjligheter och hinder samt förslag på åtgärder till förändringar inom den svenska industrin i syfte att öka energieffektiviseringsarbetet.2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Sverige är idag beroende av en säker tillgång till energi och att detta sker till konkurrenskraftiga priser. Trots att det finns både ny teknik och styrmedel för energieffektivisering så har inte den kostnadseffektiva energieffektiviseringspotentialen realiserats fullt ut. Industrin påverkas av ett antal styrmedel inom klimat- och energiområdet, som har relevans för energieffektiviseringar. Det handlar t.ex. om energi- och koldioxidskatter, utsläppshandelssystemet, elcertifikatsystem samt Programmet för energieffektivisering (PFE).

    Det råder idag en oenighet om styrmedel ska utformas som en morot eller piska för energieffektiviseringsarbetet. Detta examensarbete har tillkommit i syftet att undersöka styrmedel för att genomföra energieffektiviseringar inom den svenska industrin. Syftet är också att identifiera tänkbara möjligheter och hinder samt ge förslag på åtgärder till förändringar för att förbättra energieffektiviseringsarbetet. Examensarbetet sker också som en del av Kungliga Ingenjörsvetenskapsakademins (IVA) projekt ”Ett energieffektivt samhälle”.

    Undersökningen bygger på intervjuer med företrädare för företag, intresseorganisationer, myndigheter och andra oberoende aktörer med koppling till industrin. En litteraturstudie över nuvarande styrmedel och dess påverkan på den svenska industrin samt en internationell utblick har gjorts.

    Programmet för energieffektivisering (PFE), Energikartläggningscheckar (EKC), Miljöbalken, Ekodesign direktivet (ErP), Energi- och koldioxidskatter, Utsläppshandelsystemet (ETS) och Elcertifikatsystemet påverkar energieffektiviseringsarbetet inom industrin. Studien har visat att inget styrmedel har en total genomslagskraft på industrins aktörer. Frivilliga PFE med tydliga ekonomiska incitament och den tvingande ErP med krav på produkt och märkning anses vara ett bra och väl fungerande styrmedel. EKC kan förbättras med större incitament för de deltagande företagen. Miljöbalken kritiseras för tolkningsproblem och utdragna tillståndsprocesser. Industrins konkurrenskraft påverkas negativt av ökade skatter och ETS medan styrmedel som PFE och EKC har en positiv marknadspåverkan. Endast PFE och Miljöbalken har krav på att ett kontinuerligt energiarbete. Inget av de studerade styrmedlen är långsiktigt utformade, då det sker en kontinuerlig förändring av dessa genom antingen tolkning eller tillämpning.

    Bristfällig kunskap om energieffektiviseringar och den potential som finns för företaget att genomföra arbetet är ett stort hinder. En viktig drivkraft är därför att det finns ett tydligt informationsincitament där det klart framgår vinster med åtgärden dvs. att målet styr medlet. Resursbrister i organisationen, både vad gäller humankapital och av finansiell art, utgör hinder. Den främsta finansiella drivkraften för energieffektiviseringsinvesteringar är att det ger en avkastning på investeringen, vilket i längden bidrar till ett bättre resultat för företaget. Problem med differentierade regler och osäkerheten i att medverka i företagsöverskridande samarbeten är ett hinder. Möjligheten till att erhålla konkurrensfördelar, är den främsta drivkraften till ett utökat effektiviseringsarbete. Snedvridningar av konkurrensen och kortsiktig planering är hinder. En viktig drivkraft till energieffektiviseringslösningar inom energimarknaden är om det ger kostnadseffektiva lösningar för företaget och samhället i stort. Vad som är samhällsekonomiskt lönsamt är dock inte automatiskt företagsekonomiskt lönsamt.

    Myndigheter och företag behöver tillhandahålla klara och tydliga riktlinjer för energieffektiviseringar och uppföljning av arbetets genomförande samt redovisa vilka samhällsekonomiska och företagsekonomiska vinster som kan erhållas. Myndigheter måste ge stöd till samhällsviktiga investeringar och tillse att dessa inte påverkar konkurrenssituationen på marknaden. Långsiktighet, kostnadseffektivitet, teknikneutralitet samt att legitima aktörer deltar i processen är andra viktiga faktorer. Företag bör se till att den finansiella strukturen anpassas till att prioritera energieffektiviseringsarbetet. Industrin bör eftersträva ett kontinuerligt och långsiktighet effektiviseringsarbete genom att t.ex. lyfta fram nya nyckeltal samt att uppmuntra anställda att vara delaktiga i utvecklingsprocessen. Samarbeten, i form av samproduktion mellan universitet och högskolor, olika forskningsinstitutet, intresseorganisation och de enskilda företagen ska premieras för ökat kunskapsutbyte och minskade kostnader vad gäller effektiviseringsarbetet.

    Den svenska industrin påverkas således av ett antal styrmedel inom energiområdet. Hinder och drivkrafter kan indikera kravnivåer utifrån vilka konkreta åtgärder kan vidtas, som behövs för ett framgångsrikt energieffektiviseringsarbete. Viktigt blir att identifiera möjligheter och hinder samt att föreslå konkreta åtgärder till förändringar inom olika sektorer.

    Den centrala frågan i denna studie är om styrmedel ska vara utformat som en piska eller morot? Forskningen vad gäller energieffektiviseringar visar på att en kombination av frivilliga, tvingande och ekonomiska styrmedel behövs för en gynnsam utveckling. Aktörer med skilda intressen och förutsättningar kräver en mångfald av åtgärder som både lockar och om nödvändigt pushar aktörerna till energieffektiviseringsarbete. Respondenterna delar denna uppfattning men tillägger att om inte heterogeniteten bland aktörerna uppmärksammas fullt ut finns en fara att energieffektiviseringsarbetet missgynnas när industrin kan komma att utlokalisera till andra delar av världen för att undgå tvingande regler eller pålagor. Således kan följande slutsats dras av det anförda nämligen att den initiala frågan om styrmedel som ”piska eller morot” måste omformuleras till ett konstaterande. För ett effektivt energieffektiviseringsarbete måste både styrmedel i form av piska och morot kombineras och en bredare syn på begreppet energieffektivisering ske.  Det viktiga är en anpassning och en väl avvägd kombination av styrmedel för att gynna både energieffektiviseringsarbetet, industrin och samhället i stort.

  • 219.
    af Klintberg, Janine
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Brodin, Philip
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Kommunikation inom projekt: En analys av projektledarrollen utifrån en beteendevetenskaplig metod2010Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Många problem som uppstår inom projekt beror på dålig kommunikation. Om man på något vis kan undvika dessa kommunikationsmisstag kan man spara en hel del tid och resurser.

    En analys av hur projektledare kommunicerar har genomförts med utgångspunkt i en beteendevetenskaplig modell. Frågor som utretts är:

    1. Hur kan en projektledare kommunicera på ett så individanpassat sätt som möjligt?

    2. Vilka problem finns med individanpassad kommunikation inom ett projekt?

    Som metod för inhämtning av kunskap har en omfattande litteraturstudie genomförts för att sedan följas upp av en intervju med en sakkunnig inom den teoretiska referensram som valts. IPU Profilanalys är en metod som kategoriserar människors beteenden på ett pedagogiskt sätt. De mänskliga beteendena delas upp i fyra typer vilka allmänt kallas för Dominant, Inspiratör, Stabil och Analytisk. För att få en empirisk grund inom ämnet samt för att se hur teorin stämmer med verkligheten har tre intervjuer genomförts. Två projektledare från Ericsson respektive Statens Maritima museer samt en objektledare från Scania har intervjuats. Intervjufrågorna var av semistrukturerad karaktär och byggde på ett tänkt projekt. De omfattade såväl vilka sätt projektledaren vanligen väljer att kommunicera på som hur denne resonerar kring tekniska hjälpmedel. Syftet var att utreda hur projektledarna av- eller oavsiktligt anpassade kommunikationen efter individerna inom organisationen. Svaren från intervjuerna har sedan jämförts med teorin från IPU Profilanalys för att avgöra om individanpassad kommunikation tillämpas och i så fall hur mycket. För att kommunikationen ska bli så anpassad efter de olika grupperna projektledaren har kring sig som möjligt bör denne beakta ett antal faktorer speciellt noggrant. Dessa är:

    • En gemensam målbild
    • Varierande kommunikation
    • Ge projektmedlemmar möjlighet att förbereda sig innan möten

    Problematiken med individanpassad kommunikation visade sig främst vid stressade tidsplaner. Det visade sig även att det inte alltid var möjligt att använda sig av individanpassad kommunikation fullt ut.

  • 220.
    Af Sillén, Wilhelm
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Tillämpning av Modular Modeling med Siemens NX7.5 och Teamcenter2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    SammanfattningModular Management AB (MM) är en konsultfirma som arbetar med att implementera Modulära produktarkitekturer hos produktutvecklande företag. Företaget grundades i Stockholm år 1996 där huvudkontoret ligger än idag. De är världsledande inom sin genre och på grund av stor efterfrågan har kontor uppförts även i USAoch i Kina.Detta examensarbete är utfört på uppdrag av MM och har genomförts med hjälp av deras kunder i Finland samt kundens CAD-leverantör. Det behandlar modularisering och hur detta realiseras med hjälp av datorbaserad konstruktion (CAD). Detta är en MMs produkter och den kallas Modular Modeling. Den är sekretessbelagd, varpå större delar av resultaten är uteslutna i rapporten.Målet är att hitta en flexibel, robust och samtidigt lättanvänd metod för att tillämpa Modular Modeling i Siemens NX 7.5 i kontext av Product Lifecycle Management- (PLM) systemet Teamcenter. MM har tidigare tillämpat Modular Modeling™ med liknande arbeten för programvarorna ProEngineer och Solidworks.Arbetet inleddes med studier och analysering av modularisering och mjukvarorna som använts. Analysen resulterade i en kravlista som omformats till operationer, som krävs för att till fullo stödja Modular Modeling. Lösningar till operationerna söktes med hjälp av modellering i NX och Teamcenter. Dessa lösningar utvärderades sedan metodiskt varpå en fullständig metod kunde erhållas.Under arbetets gång har de största svårigheterna varit att hitta alternativa lösningar då en specifik funktionalitet saknas i programvaran samt att få tillgång till en Teamcenter testmiljö.Arbetetsresultat är en metod som till fullo stödjer Modular Modeling även om ett par operationer behöver lite extra åtgärder. Metoden har dokumenterats i form av en användarguide som ska användas av MMs kunder samt presentationsmaterial som ska användas av MMs konsulter för att kommunicera metoden.

  • 221.
    AFEWORK, YARED
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    VALTERSSON, MAGNUS
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Guiding Shirt: Aiding the Visually Impaired Using Wearable Technology2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The purpose of this thesis was to research how wearable technology mounted on the torso can be used to aid the visually disabled, particularly in their ability to move around in the world. The project was divided into two parts: the first on how to help them avoid obstacles in their paths, the second on how to help guide them to a specific destination using a navigation system.

    The obstacle avoidance system is composed of a number of ultrasonic sensors for distance measuring purposes, each of which are paired to their own vibration motor which provides a tactile feedback to the person. The intensity of each vibration motors are proportional to the distance measured by the corresponding ultrasonic sensor, allowing for the user to get an intuitive feeling of the distance to various objects in the space surrounding them.

    The navigation system is composed of a GPS sensor, magnetometer and a collection of stored GPS coordinate checkpoints. By comparing the real-time position of the user with a stored goal GPS coordinate, a guiding direction and a distance measurement is calculated. The distance measurement is used to keep track of when a new goal GPS coordinate should be loaded. The magnetometer is used as a compass and its value is compared to the guiding direction, providing a degree error. Tactile feedback is provided using vibration motors, making the user aware of how they should turn their body.

  • 222. Affatato, S.
    et al.
    Leardini, W.
    Jedenmalm, Anneli
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Ruggeri, O.
    Toni, A.
    Larger diameter bearings reduce wear in metal-on-metal hip implants2007Inngår i: Clinical Orthopaedics and Related Research, ISSN 0009-921X, E-ISSN 1528-1132, nr 456, s. 153-158Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Metal-on-metal hip arthroplasty has the longest clinical history of all total arthroplasties. We asked whether large diameter femoral heads would result in less wear than those with small diameters. We also asked if there is a threshold diameter that ensures good wear behavior. We tested three batches of cast high-carbon cobalt-chromium-molybdenum hip implants (28 mm, 36 min, and 54 min diameters) in a hip simulator for 5 million cycles. We used bovine serum as lubricant and weighed the samples at regular intervals during testing. The 28-mm configuration had almost twice the wear of the 54-mm configuration, but we observed no difference between the 36-mm and the 54-mm configurations. The similarity in the wear performances of the larger configurations supports the presence of a threshold diameter that ensures good wear behavior.

  • 223. Affatato, S.
    et al.
    Leardini, W.
    Jedenmalm, Anneli
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Zavalloni, M.
    Ruggeri, O.
    Tarterini, F.
    Viceconti, M.
    Microstructural effects on the wear resistance of CO-CR implant alloys2006Inngår i: Proceedings of the 8th Biennial Conference on Engineering Systems Design and Analysis, 2006, s. -951Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Modem metal-on-metal articulation have been proposed to reduce the incidence of osteolysis due to polyethylene particles debris, as a late complication. The tribology of large metal-on-metal articulations allows theoretical advantages with respect to other configurations, especially for the lubrication regime. This study was aimed to compare the wear performances of different diameters of clinically available acetabular metallic components manufactured in a cast cobalt-chrome alloy. To evaluate the influence of the material properties of wear and microstructure, metal-on-metal components were tested in a hip joint simulator for five million cycles with bovine calf serum as lubricant. In particular, three different configurations of metal-on-metal components (28-mm, 36-mm, 54-mm) were tested. After the test all specimens were examined with optical and electronic scanning microscope. A statistical difference were observed among the three groups tested in the run-in and steady-state wear rates, favoring the larger femoral heads. The results of this study indicate that the 54-mm diameter femoral heads prove a better wear behavior than the smaller configurations.

  • 224.
    Afraz, Syed Ali
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Mechanical, Microstructural and Corrosion performance for MIM materials based on coarse (-45µm) powders of ferritic stainless steel2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The purpose of this research is to investigate the mechanical, microstructural and corrosion performance of the ferritic stainless steel coarse powders, used in Metal Injection Molding (MIM) process. Three coarser powders made by Höganäs AB, were examined along with a commercially available fine MIM powder and samples from sheet metal. The studied powders were individually mixed with binders and then injection molded in the shape of dog bone shaped tensile bars. These green samples were then debinded and sintered to examine under different characterization methods. The methods used for examining the samples were tensile test, hardness test, metallography, SEM, chemical analysis, and salt spray test. After a comparative study of these different materials, it turns out that the chemical composition and the process parameters have more effect on materials properties compared to only particle size distribution in studied materials. After this study, 434 coarse powder was preferred upon the PolyMIM 430 fine powder, because of its lower price and same performance as that of PolyMIM 430.

  • 225.
    Afshari, Arsham
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Li, John-Ting
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Product Development: The theory and its applicability in practice2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This paper is a qualitative research to understand how well the theoretical methods of product development are applied in practice. A comparison between the theory and methods the companies are using is done in order to get an insight of the current situation. Value analysis, Quality Function Deployment, Failure Mode and Effects Analysis, Design for Assembly, and Modular Function Deployment that is brought up in this thesis are all well-known methods in the theory which assist companies to achieve a higher degree and effectiveness with their development. These methods answer fundamental problems that may occur in every company, and touches on areas such as the economical perspectives and customer related inquiries. It also finds solutions on uncertainties that might arise during product development. After interviewing ABB, Scania and Atlas Copco, we learned that some of the theoretical methods were in fact utilized to a certain degree. However, there are instances where the enterprises establish their own principles to rationalize product development. After a thorough comparison made between the methods used by the companies and the theory, we discovered many similarities between them. The foundations of these methods are very much based on the existing theories. We concluded that even though the theoretical methods aren’t applicable to all situations, the fundamentals are widely accepted and the philosophies behind them are commonly applied in companies’ own methods. The theory does not only act as a backbone for effective product development but also serves as an important tool for further method customization suitable to the uniqueness of each enterprise. Lack of knowledge in the actual theories can therefore undermine the companies’ capability in achieving efficient methods which ultimately will only disfavor themselves in terms of time and money. Companies spend a lot of time to discover methods to facilitate their development processes. They can instead collaborate with academic institutes and universities to exchange information since theories already exist out there that are able to answer and solve most the companies’ current situation and their requirements. However, there are occasions in real life circumstances where things doesn’t necessary go as smooth as depicted in literatures and theories. Therefore a balance between practice and theory where they complement each other will yield the optimal outcome.

  • 226.
    Afsharian, Reza
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Theodoropoulos, Antonios
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Modular friction test rig for measuring torque and tension in threaded fasteners2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This report describes the development of a modular friction test rig for threaded fasteners. This device can measure the shank torque and the clamp force during the tightening of threaded bolts, with a size of M3-M14 and clamp length of 30-160mm. The design allows the use of several load and torque cells and the range is up to 100kN clamp load and 200Nm applied torque. The test rig will be used for research purposes by Atlas Copco to determine the frictional characteristics in tightening and will allow the experiments on bolts with several materials, coatings and surface finishes. This report concludes to a design proposal evaluated with analytical methods and a prototype 3D model that demonstrate the working principle of the test rig. The measurements are taken from custom-made sensors that are developed with high standards, are easily interchangeable and can be calibrated individually. In addition, a device is developed to allow the user to change the stiffness of the joint. Finally, a future recommendation is made to allow the measurement of the under-head torque. This proposal is a breakthrough compared to other test rigs, and will assist in verifying the friction measurements and having high precision results.

  • 227.
    Aftab, Ahmad
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Model-based design of haptic devices2012Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Efficient engineering design and development of high precision and reliable surgical simulators, like haptic devices for surgical training benefits from model-based and simulation driven design. The complexity of the design space, multi-domains, multicriteria requirements and multi-physics character of the behavior of such a product ask for a model based systematic approach for creating and validating compact and computationally efficient simulation models to be used for the design process.The research presented in this thesis describes a model-based design approach towards the design of haptic devices for simulation of surgical procedures, in case of hard tissues such as bone or teeth milling. The proposed approach is applied to a new haptic device based on TAU configuration.The main contributions of this thesis are:

    • Development and verification of kinematic and dynamic models of the TAU haptic device.
    • Multi-objective optimization (MOO) approach for optimum design of the TAU haptic device by optimizing kinematic performance indices, like workspace volume, kinematic isotropy and torque requirement of actuators.
    •  A methodology for creating an analytical and compact model of the quasi-static stiffness of haptic devices, which considers the stiffness of; actuation system;flexible links and passive joints.
  • 228.
    Aftab, Ahmad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Sellgren, Ulf
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Khan, Suleman
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    A stiffness modeling methodology for simulation-driven design of haptic devices2014Inngår i: Engineering with Computers, ISSN 0177-0667, E-ISSN 1435-5663, Vol. 30, nr 1, s. 125-141Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Efficient development and engineering of high performing interactive devices, such as haptic robots for surgical training benefits from model-based and simulation-driven design. The complexity of the design space and the multi-domain and multi-physics character of the behavior of such a product ask for a systematic methodology for creating and validating compact and computationally efficient simulation models to be used in the design process. Modeling the quasi-static stiffness is an important first step before optimizing the mechanical structure, engineering the control system, and performing hardware in the loop tests. The stiffness depends not only on the stiffness of the links, but also on the contact stiffness in each joint. A fine-granular Finite element method (FEM) model, which is the most straightforward approach, cannot, due to the model size and simulation complexity, efficiently be used to address such tasks. In this work, a new methodology for creating an analytical and compact model of the quasi-static stiffness of a haptic device is proposed, which considers the stiffness of actuation systems, flexible links and passive joints. For the modeling of passive joints, a hertzian contact model is introduced for both spherical and universal joints, and a simply supported beam model for universal joints. The validation process is presented as a systematic guideline to evaluate the stiffness parameters both using parametric FEM modeling and physical experiments. Preloading has been used to consider the clearances and possible assembling errors during manufacturing. A modified JP Merlet kinematic structure is used to exemplify the modeling and validation methodology.

  • 229.
    Aftab, Ahmad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Khan, Suleman
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Mekatronik.
    Andersson, Kjell
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Kinematics and Dynamics of a novel 6-DoF TAU Haptic Device2011Inngår i: Proceedings of the 2011 IEEE International Conference on MechatronicsInternational Conference on Mechatronics, April 13-15, 2011, Istanbul, Turkey, IEEE conference proceedings, 2011, s. 719-724Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the kinematics and dynamics modeling of a novel hybrid kinematic concept, i.e. the TAU haptic device. This new concept was obtained from the modification of TAU-2 structure proposed by Khan et al. First a kinematic model for inverse and forward kinematics was developed and analyzed. Then an algorithm to solve the close form inverse dynamics is presented using Lagrangian formulation. Numerical simulation was carried out to examine the validity of the approach and accuracy of the technique employed. A trigonometric helical trajectory of 5th order spline was developed in Cartesian space for each degree of freedom of the moving platform in order to verify and simulate the inverse dynamics; the motion of the platform is such that the tool centre point remains on this trajectory while its orientation is changing constantly in roll, pitch and yaw.

  • 230.
    Afzal, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Nanocomposite Materials for New Energy Conversion Device2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis gives an approach how to develop newperovskite and nanocomposite cathode material for low temperature solid oxidefuel cells on the basis of nanocomposite approach to lower the operatingtemperature of SOFC. BaxCa1-xCoyFe1-yO3-δ(BCCF) and BSCF perovskite or nanocomposite oxides have been synthesized andinvestigated as catalytically potential cathode materials for low temperaturesolid oxide fuel cells (LTSOFC). Some single component materials have been alsosynthesized for new energy conversion device or EFFC. These nanocomposite andperovskite electrical conductors were synthesized by wet chemical, sol gel,co-precipitation and solid state reaction methods. Comparison with that ofcommercial Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF) cathode material, BCCF and locally prepared BSCF exhibit higher electricalconductivities as compared to that of commercial BSCF at same setup andconditions. In particular, novel Ba0.3Ca0.7Co0.8Fe0.2O3-δhas shown the maximum conductivity of 143 S/cm in air and local BSCF withconductivity of 313 S/cm in air at 550°C were measured by DC 4 probe method. Anadditional positive aspect of BCCF is that it is cost effective and works atroom temperature but with small output which will lead SOFC to operate atextremely low temperatures. XRD patterns of the samples reveal perovskite andnanocomposite structures of the said materials. Microstructure studies give thehomogeneous structure and morphology of the nanoparticles by using HighResolution Scanning Electron Microscopy (SEM). Cell resistance has beendetermined by Electrochemical Impedance Spectroscopy (EIS). Devised materialshave shown very good mechanical strength and stability proving their importancein advanced fuel cell technology. Power density of devices from 126 to 192 mWcm-2hasbeen achieved.

  • 231.
    Afzal, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Semiconductor-ionic Materials for Low Temperature Solid Oxide Fuel Cells2019Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Solid oxide fuel cell (SOFC) is considered as an attractive candidate for energy conversion within the fuel cell (FC) family due to several advantages including environment friendly, use of non-noble materials and fuel flexibility. However, due to high working temperatures, conventional SOFC faces many challenges relating to high operational and capital costs besides the limited selection of the FC materials and their compatibility issues. Recent SOFC research is focused on how to reduce its operational temperature to 700 ºC or lower. Investigation of new electrolytes and electrode materials, which can perform well at low temperatures, is a comprehensive route to lowering the working temperature of SOFC. Meanwhile, semiconductor-ionic materials based on semiconductors (perovskite/composite) and ionic materials (e.g. ceria based ion conductors) have been identified as potential candidates to operate in low temperature range with adequate SOFC power outputs.

    This investigation focuses on the development of semiconductor-ionic materials for low temperature solid oxide fuel cell (SOFC) and electrolyte-layer free fuel cell (EFFC). The content of this work is divided into four parts:

    First part of the thesis consists of the work on conventional SOFC to build knowledge and bridge from conventional SOFC to the new EFFC. Novel composite electrode (semiconductor) materials are synthesized and studied using established electrochemical and analytical methods such as x-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The phase structure, morphology and microstructure of the composite electrodes are studied using XRD and SEM, and the weight loss is determined using TGA. An electrical conductivity of up to 143 S/cm of as-prepared material is measured using DC 4 probe method at 550 ºC. An electrolyte, samarium doped ceria (SDC) is synthesized to fabricate a conventional three component SOFC device. The maximum power density of 325 mW/cm2 achieved from the conventional device at 550 ºC.

    In the second part of the thesis, semiconductor-ionic materials based on perovskite and composite materials are prepared for low temperature SOFC and EFFC devices. Semiconductor-ionic materials are prepared via nanocomposite approach based on two-phase semiconductor electrode and ionic electrolyte. This semiconductor-ionic functional component was shown to integrate all fuel cell components anode, electrolyte and cathode functions into a single component, i.e. “three in one”, resulting in enhanced catalytic activity and improved SOFC performance.

    The third part of the thesis addresses the development and optimization of the EFFC technologies by studying the Schottky junction mechanism in such semiconductor-ionic type devices. Perovskite and functional nanocomposites (semiconductor-ionic materials) are developed for EFFC devices. Materials characterizations are performed using a number of standard experimental and analytical techniques. Maximum power densities from 600 mW/cm2 up to 800 mW/cm2 have been achieved at 600 ºC.

    Fourth part of the thesis describes the theoretical simulation of EFFCs. In this work, an updated numerical model is applied in order to study the EFFC device, which introduces some modifications to the existing relations for traditional fuel cell models. The simulated V-I and P-I curves have been compared with experimental curves, and both types of curves show a good consistency.

  • 232.
    Afzal, Muhammad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Madaan, Sushant
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Dong, Wenjing
    Raza, Rizwan
    Xia, Chen
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Zhu, Bin
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi. Hubei University, China.
    Analysis of a perovskite-ceria functional layer-based solid oxide fuel cell2017Inngår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, nr 27, s. 17536-17543Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A fuel cell based on a functional layer of perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) composited samarium doped ceria (SDC) has been developed. The device achieves a peak power density of 640.4 mW cm(-2) with an open circuit voltage (OCV) of 1.04 Vat 560 degrees C using hydrogen and air as the fuel and oxidant, respectively. A numerical model is applied to fit the experimental cell voltage. The kinetics of anodic and cathodic reactions are modeled based on the measurements obtained by electrochemical impedance spectroscopy (EIS). Modeling results are in well agreement with the experimental data. Mechanical stability of the cell is also examined by using analysis with field emission scanning electron microscope (FESEM) associated with energy dispersive spectroscopy (EDS) after testing the cell performance.

  • 233.
    Afzal, Muhammad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Saleemi, Mohsin
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Material- och nanofysik.
    Wang, Baoyuan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Xia, Chen
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Zhang, Wei
    He, Yunjuan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Jayasuriya, Jeevan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Zhu, Binzhu
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fabrication of novel electrolyte-layer free fuel cell with semi-ionic conductor (Ba0.5Sr0.5Co0.8Fe0.2O3-delta- Sm0.2Ce0.8O1.9) and Schottky barrier2016Inngår i: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 328, s. 136-142Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) is synthesized via a chemical co-precipitation technique for a low temperature solid oxide fuel cell (LTSOFC) (300-600 degrees C) and electrolyte-layer free fuel cell (EFFC) in a comprehensive study. The EFFC with a homogeneous mixture of samarium doped ceria (SDC): BSCF (60%:40% by weight) which is rather similar to the cathode (SDC: BSCF in 50%:50% by weight) used for a three layer SOFC demonstrates peak power densities up to 655 mW/cm(2), while a three layer (anode/ electrolyte/cathode) SOFC has reached only 425 mW/cm(2) at 550 degrees C. Chemical phase, crystal structure and morphology of the as-prepared sample are characterized by X-ray diffraction and field emission scanning electron microscopy coupled with energy dispersive spectroscopy. The electrochemical performances of 3-layer SOFC and EFFC are studied by electrochemical impedance spectroscopy (EIS). As-prepared BSCF has exhibited a maximum conductivity above 300 S/cm at 550 degrees C. High performance of the EFFC device corresponds to a balanced combination between ionic and electronic (holes) conduction characteristic. The Schottky barrier prevents the EFFC from the electronic short circuiting problem which also enhances power output. The results provide a new way to produce highly effective cathode materials for LTSOFC and semiconductor designs for EFFC functions using a semiconducting-ionic material.

  • 234.
    Afzal, Muhammad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Xia, Chen
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Zhu, Bin
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi. Hubei University, China.
    Lanthanum-doped Calcium Manganite (La0.1Ca0.9MnO3) Cathode for Advanced Solid Oxide Fuel Cell (SOFC)2016Inngår i: MATERIALS TODAY-PROCEEDINGS, ELSEVIER SCIENCE BV , 2016, Vol. 3, nr 8, s. 2698-2706Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present here a new perovskite oxide with low lanthanum content doped in calcium manganite, La0.1Ca0.9MnO3 (LCM) as a functional material for low temperature solid oxide fuel cell (LTSOFC) and electrolyte-layer free fuel cell (EFFC). The LCM introduces an intrinsic mixed-ion and electron conduction. Electrochemical impedance spectroscopy (EIS) analysis shows high oxygen reduction reaction (ORR) activity with an extremely low activation energy which enables an excellent cathode activity. Fuel cells using LCM as cathode with oxide ion conducting electrolyte samarium doped ceria (SDC) and NCAL as an anode, demonstrate a maximum power density of 650 mW cm(-2) at 550 degrees C, which is higher than most of the cathode materials reported for SOFC at this temperature. For EFFC, maximum power density of 750 mW cm(-2) is achieved using LCM as a semiconductor material with SDC ion conducting material. The present work highlights the development of new active air electrode especially for developing low temperature solid oxide fuel cells.

  • 235.
    Aga, Aboma Emiru
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fuel Supply Investigation for an Externally Fired Microturbine based Micro CHP System: Case study on a selected site in Bishoftu, Ethiopia2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Sudden change on earth’s climate, which is a result of an increase in CO2 in the atmosphere, is mainlycaused by burning of fossil fuels for various energy services. However, for the energy services to befavourable to the environment, there should be a balance with the environmental protection, and we cancall that “Sustainable Innovative Development”.

    “EXPLORE Polygeneration” initiative will serve as an important tool to promote the application ofrenewable technologies extending to the future sustainable energy engineering field. This paper is intendedin investigating a suitable fuel supply for the microturbine based micro CHP system available at theDivision of Heat and Power Technology, KTH, Sweden; for a site called “Alema Farm PLC”, Bishoftu,Ethiopia.

    Though there is a large biomass energy resource and a huge potential to produce hydroelectric power inEthiopia, the modern energy sector is very small and the energy system is mainly characterized by biomassfuel supplies and household energy consumption. The nation’s limited biomass energy resource is believedto have been depleting at an increasingly faster rate.

    Of the many and surplus amount of renewable energy resources available in and around Alema FarmPLC, poultry litter and pig’s manure are selected to be the two main energy sources for the CHP systemavailable in the lab, after passing through different conversion techniques. However, after consideringsome basic properties like: Energy content and Bulk Density of the fuel, Moisture content , Ashcharacteristic, Tar content, Fuel logistics, Local storage, Fuel feeder system, and Magnitude of GHGReduction; poultry litter is found to be the most convenient to produce a syngas with a Downdraftatmospheric gasifier available in the HPT lab.

    Finally, For the problems caused by the nature of the poultry litter by itself and the methods used in theconversion process, the 40 TRIZ principles of TRIZ inventive principles is used and some major pointsare recommended.

  • 236.
    Agarwal, Rohit
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    User Interface Design of Head-Up Display Using Scenarios: An Early Stage Innovation Project at Bombardier2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Head-up display (HUD) är en beprövad teknik inom flyg och bil, vilken gör det möjligt för piloter och förare att få tillgång till information utan att uppmärksamheten avleds från omvärlden. Liknande fördelar kan uppnås genom installation av HUD i tåg.

    Syftet med denna studie är att utveckla ett användargränssnitt för HUD baserat på European Rail Traffic Management System (ERTMS). HUD kommer att vara en extra säkerhetsfunktion för tågen för att förhindra förare från att skifta fokus mellan instrumentpanelen och omgivningen, vilket leder till minskad förareutmattning och bättre observation av spåren framåt. Scenario Based Design-metoden har använts för att genomföra projektarbetet och i rapporten diskuteras metodens  fördelar och begränsningar. Användningen av scenarier har gjort det möjligt för designteamet att på djupet förstå de situationer som förarna står inför samt  har hjälpt till att under workshops få en bättre förståelse för drivrutinerna.

    Dessutom har rekommendationer för hårdvara, installation och framtida arbete beskrivits för fortsatt genomförande av projektet.

  • 237.
    Ageng, Pandu SW
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi.
    Jeneberang River Basin Management Capacity: Establishing of a Public Corporate in South Sulawesi Province in INDONESIA2005Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A multi purpose dam called Bili bili have been built in Jeneberang river basin in easternIndonesia in 1999 and providing water available to all customers. In 2004 a landslide occurredand impact to the quality of raw water, especially the amount of turbidity, dramaticallyincreased. Landslide problems started with high sedimentation rates to water infrastructures.Technically the lifetime of Bili bili multi purpose dam and reservoirs will be shorter thanplanned. In contrast, we understand and agreed that sustainable development and ensuring thecurrent use of a water resource as well as a dam should compromise its use by future generation.To reach progress in sustainability we need to establish governance structures and practices thatcan foster, guide and coordinated positive work by a host of actors on a complex of issues.Today, Indonesian Central Government is planning to establish a public corporate participationto comprehensive water resources management in eastern Indonesia. The important significant ofstakeholders in order to develop comprehensive approaches, are water agencies: regional andlocal water institution that will manage catchments areas, water infrastructures and water utilitiesas provider of drinking water to municipalities. They will be acquainted to the water and waterinstitutional capacity problems.

    This research examines both the current impacts on and potential future for water management ineastern Indonesia. One of the objectives of this research will be to described the current of waterresource organization, which is related to establishing of a public corporate, not onlystakeholders involvement; management and organization; but also finances and investments;operation; distribution; regulation and policy. One objective of this research will be measured byconducting interactive interviews and dialogue with the representatives of the stakeholders. Thelast objective is evaluating the Human Resources Development performances of water resourcesmanagement by a series of workshops. Additionally, some recommendations for a future watersupply system will be provided as an input for the government and local authority in order toimprove the capacity and water resources management in eastern Indonesia.

    The results conclude that to meet the Millennium Development Goals, the establishment of apublic corporate for supporting Indonesia’s process of decentralization is necessary where thelocal level include customers can be a much more dynamic interaction between providers ofservices and water users. A participatory method is useful to raise problems, so while the CentralGovernment can mandate a minimum service standard and the achievements of these standardscan be monitored directly at the local level.

    Accountability of water resources development should be considered as a vehicle when aproblem occurs with insufficiency of the existing water facilities and a big demand of waterpurposes.

  • 238.
    Agerberg, Anton
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    Carlson, Catja
    KTH, Skolan för industriell teknik och management (ITM), Industriell produktion.
    PHOTOVOLTAIC ELECTRIFICATION IN CAMEROON: - A study for the Renewable Energy Program initiated by Engineers Without Borders SWE2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In Sub-Saharan Africa where the rural electrification rates are below 20%, many are positive about renewable energy sources being the salvation for the electricity problem in the area. Engineers Without Borders Sweden has also recognized this and intends to enable a quicker implementation through the Renewable Energy Program. The programme aims to sustainably increase the spread of renewable energy sources by enhancing the possibilities for local entrepreneurs active in the sector. In the Central-African country Cameroon, found at the Gulf of Guinea, the solar irradiation is intense all year round, making solar power a potential energy source for electricity in the country's rural areas. The work presented in this thesis has had the objective to identify and address the financial and technical challenges of spreading the use of solar energy through photovoltaic solutions in Cameroon, in order to enable a successful implementation of the Renewable Energy Program in the country. To gain local insights, a field study was performed in the rural village of Tatum in north-western Cameroon where the authors began by identifying the stakeholders for the implementation of the Renewable Energy Program. Then we proceeded by conducting interviews and distributing questionnaires. A number of challenges became clear. The most obvious one being that photovoltaic technology is expensive, thus not being affordable for the average rural household. However, the study also showed that within the security of a structured program many households would be willing to make the investment. Furthermore, the study showed that lack of knowledge in the households together with a major lack of local technicians would be additional obstacles. The latter being answered with a belief in a spread organically, through a strong word of mouth culture, the first with the idea of a trainee programme. The ideas are analysed through models and as a conclusion the authors state a belief that despite a number of challenges ahead, the Renewable Energy Program is a strong concept that will succeed with its mission.

  • 239.
    Agerberg, Anton
    et al.
    KTH, Skolan för industriell teknik och management (ITM).
    von Sydow Yllenius, Trolle
    KTH, Skolan för industriell teknik och management (ITM).
    Creating Shared Value through Strategic Biobanking: Public-Private Partnerships in Healthcare2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Societies are plagued by growing healthcare expenditures and budgetary constraints. The strategy for solving the issue has been heavily debated, with proposed solutions such as Valuebased healthcare (VBHC), Public-Private Partnerships (PPP) and improved medical treatments. A novel concept that aims to improve medical treatment is strategic biobanking. Strategic biobanking is the act of saving biological samples and clinical data for future research. Access to strategic samples can speed up future clinical trials and studies, provide researchers with more useful research material, enable more thorough analyses of biomarkers, facilitate faster drug development, and increase the power of both retrospective analyses and precision medicine.

    This thesis studies the shared value effects of a strategic biobanking PPP by drawing on the theoretical fields of VBHC, PPP and Creating Shared Value (CSV).

    Specifically, the effects of hospital organisational structure, regulatory framework and public interest on strategic biobanking PPPs was studied.

    The research was carried out through a single holistic case study of Karolinska University Hospital in Stockholm, Sweden and multiple pharmaceutical companies, and data was collected through semi-structured interviews. Data analysis was carried out in accordance with the grounded theory framework.

    The researchers find that regulatory structure can limit the options when crafting the business model and the industry value proposition for a strategic biobanking PPP. Some strategies on how to deal with these restraints are outlined.

    Furthermore, the research highlights the importance of longitudinal data-sets and how a hospital organised according to the VBHC principles is more suitable for implementation of longitudinal sampling routines.

    Finally, the research shows that that the concept of CSV can act as guidance for private partner decision making to increase public interest. By adopting principles of transparency regarding financial incentives and motivations, an industry partner can garner increased trust with the general public as well as their public partner. The shared value effects are pronounced, and the study finds that a strategic biobanking PPP moves the boundary for what is scientifically possible for all stakeholders in the healthcare domain.

  • 240.
    Ageyev, Victor
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Heating Tariff System In Donetsk2011Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In different countries, such as Ukraine and Sweden, there have been differences in the way of administrating the systems which dictate the way of living and the way the societies function. Different approaches have been adopted over the time when it came to setting up the rules for how the state´s vital organizations, such as tax administration, health care, police, army, education system and many others should work and function. The idea in many modern countries is the same, but the ways and procedures can differ a great deal from country to country. This applies to the sphere of district heating services as well.

    The purpose of this thesis is to gain understand with the help of economic theory why heating tariffs are managed in a country that has had transition from plan economy to market economy the way they are, and how the management of heating tariffs could be improved when taking into account the experience of a country with long established market economy. During field studies performed in Sweden and Ukraine, particularly in the city of Donetsk, a comparative analysis of the two heating tariff systems have been performed in order to outline and highlight the differences between them and to answer the main questions of the study.

    The results include the status report of the situation concerning the district heating tariff systems in Sweden and Ukraine, comparative analysis of the two systems and suggestion on improvements of the district heating tariff system in the city of Donetsk. The outcomes and suggested improvements do not provide the full picture and all the aspects of the situation, due to the fact that more extensive studies, involving larger resources, would have to be conducted in the area. However, the report provides a good starting point for further studies within the field of district heating tariffs in Ukraine and Sweden.

  • 241.
    Agge, Tor
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Incitament för att skapa innovativa produkter2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    För företag verksamma inom produktutveckling är innovation otroligt viktigt för konkurrens-kraften. Begreppet innovation används här för att benämna den framgångsrika idén. Det finns många sätt att främja innovation och i detta sammanhang används begreppet incitament. Incitament är en benämning på åtgärder som har som syfte att uppmuntra ett särskilt beteende. Detta arbete syftar därför till att undersöka hur företag använder incitament för att främja innovation. Fokus ligger på att undersöka hur incitament främjar det interna idéskapandet samt hur kreativitet kan stimuleras.

    Arbetet baseras på en litteraturstudie och en empirisk studie. Vetenskapliga artiklar samt böcker har används i litteraturstudien för ge en teoretisk och aktuell grund. Den empiriska studien utgörs av intervjuer på sju stycken företag verksamma inom produktutveckling i Sverige. Intervjuerna har utförts med hjälp av en semistrukturerad intervjuguide för att intervjuerna ska ge en så komplett och relevant information som möjligt. Trots detta kan de olika intervjuernas omfattning variera och det är möjligt att resultatet inte är representativt för hela företaget.

    Resultatet från intervjuerna analyserades med den teoretiska bakgrunden i åtanke och utifrån detta kunde många likheter mellan företagen noteras. Särskilt lyckade idéer och prestationer uppmärksammas ofta. Belöningar av ekonomisk karaktär visade sig däremot användas i väldigt liten utsträckning och tycks inte vara en drivkraft för kreativitet eller idéskapande. Det finns många olika sätt att motivera medarbetare till att komma med idéer men det som visat sig vara centrala motivatorer är frihet för kreativitet och samarbete under idéskapandet.  

  • 242.
    Aghaali, H.
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Ångström, H. -E
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Improving turbocharged engine simulation by including heat transfer in the turbocharger2012Inngår i: SAE technical paper series, ISSN 0148-7191Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Engine simulation based on one-dimensional gas dynamics is well suited for integration of all aspects arising in engine and powertrain developments. Commonly used turbocharger performance maps in engine simulation are measured in non-pulsating flow and without taking into account the heat transfer. Since on-engine turbochargers are exposed to pulsating flow and varying heat transfer situations, the maps in the engine simulation, i.e. GT-POWER, have to be shifted and corrected which are usually done by mass and efficiency multipliers for both turbine and compressor. The multipliers change the maps and are often different for every load point. Particularly, the efficiency multiplier is different for every heat transfer situation on the turbocharger. The aim of this paper is to include the heat transfer of the turbocharger in the engine simulation and consequently to reduce the use of efficiency multiplier for both the turbine and compressor. A set of experiment has been designed and performed on a water-oil-cooled turbocharger, which was installed on a 2 liter GDI engine with variable valve timing, for different load points of the engine and different conditions of heat transfer in the turbocharger. The experiments were the base to simulate heat transfer on the turbocharger, by adding a heat sink before the turbine and a heat source after the compressor. The efficiency multiplier of the turbine cannot compensate for all heat transfer in the turbine, so it is needed to put out heat from the turbine in addition to the using of efficiency multiplier. Results of this study show that including heat transfer of turbocharger in engine simulation enables to decrease the use of turbine efficiency multiplier and eliminate the use of compressor efficiency multiplier to correctly calculate the measured gas temperatures after turbine and compressor. 

  • 243.
    Aghaali, Habib
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Exhaust Heat Utilisation and Losses in Internal Combustion Engines with Focus on the Gas Exchange System2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Exhaust gas energy recovery should be considered in improving fuel economy of internal combustion engines. A large portion of fuel energy is wasted through the exhaust of internal combustion engines. Turbocharger and turbocompound can, however, recover part of this wasted heat. The energy recovery depends on the efficiency and mass flow of the turbine(s) as well as the exhaust gas state and properties such as pressure, temperature and specific heat capacity. The exhaust gas pressure is the principal parameter which is required for the turbine energy recovery, but higher exhaust back-pressures on the engines create higher pumping losses. This is in addition to the heat losses in the turbochargers what makes any measurement and simulation of the engines more complex.

    This thesis consists of two major parts. First of all, the importance of heat losses in turbochargers has been shown theoretically and experimentally with the aim of including heat transfer of the turbochargers in engine simulations. Secondly, different concepts have been examined to extract exhaust heat energy including turbocompounding and divided exhaust period (DEP) with the aim of improved exhaust heat utilisation and reduced pumping losses.

    In the study of heat transfer in turbochargers, the turbocharged engine simulation was improved by including heat transfer of the turbocharger in the simulation. Next, the heat transfer modelling of the turbochargers was improved by introducing a new method for convection heat transfer calculation with the support of on-engine turbocharger measurements under different heat transfer conditions. Then, two different turbocharger performance maps were assessed concerning the heat transfer conditions in the engine simulation. Finally, the temperatures of turbocharger’s surfaces were predicted according to the measurements under different heat transfer conditions and their effects are studied on the turbocharger performance. The present study shows that the heat transfer in the turbochargers is very crucial to take into account in the engine simulations, especially in transient operations.

    In the study of exhaust heat utilisation, important parameters concerning turbine and gas exchange system that can influence the waste heat recovery were discussed. In addition to exhaust back-pressure, turbine speed and turbine efficiency, the role of the air-fuel equivalence ratio was demonstrated in details, because lower air-fuel equivalence ratio in a Diesel engine can provide higher exhaust gas temperature. The results of this study indicate that turbocompound engine efficiency is relatively insensitive to the air-fuel equivalence ratio.

    To decrease the influence of the increased exhaust back-pressure of a turbocompound engine, a new architecture was developed by combining the turbocompound engine with DEP. The aim of this study was to utilise the earlier phase (blowdown) of the exhaust stroke in the turbine(s) and let the later phase (scavenging) of the exhaust stroke bypass the turbine(s). To decouple the blowdown phase from the scavenging phase, the exhaust flow was divided between two different exhaust manifolds with different valve timing.

    According to this study, this combination improves the fuel consumption in low engine speeds and deteriorates it at high engine speeds. This is mainly due to long duration of choked flow in the exhaust valves because this approach is using only one of the two exhaust valves on each cylinder at a time.

    Therefore, the effects of enlarged effective flow areas of the exhaust valves were studied. Two methods were used to enlarge the effective flow area i.e. increasing the diameters of the blowdown and scavenging valves by 4 mm; and modifying the valve lift curves of the exhaust valves to fast opening and closing. Both methods improved BSFC in the same order even though they were different in nature. Fast opening and closing of the exhaust valves required shorter blowdown duration and longer scavenging duration. The modified lift curves provided less pumping losses, less available energy into the turbine and larger amplitude of the pulsating flow through the turbine.

    In order for defining a set of important parameters that should be examined in experimental studies, a sensitivity analysis was performed on the turbocompound DEP engine in terms of break specific fuel consumption to different parameters concerning the gas exchange such as blowdown valve timing, scavenging valve timing, blowdown valve size, scavenging valve size, discharge coefficients of blowdown and scavenging ports, turbine efficiency, turbine size and power transmission efficiency.

    Finally, to overcome the restriction in the effective flow areas of the exhaust valves, DEP was implemented externally on the exhaust manifold instead of engine exhaust valves, which is called externally DEP (ExDEP). This innovative engine architecture, which benefits from supercharging, turbocharging and turbocompounding, has a great fuel-saving potential in almost all load points up to 4%.

  • 244.
    Aghaali, Habib
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    On-Engine Turbocharger Performance Considering Heat Transfer2012Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Heat transfer plays an important role in affecting an on-engine turbocharger performance. However, it is normally not taken into account for turbocharged engine simulations.

    Generally, an engine simulation based on one-dimensional gas dynamics uses turbocharger performance maps which are measured without quantifying and qualifying the heat transfer, regardless of the fact that they are measured on the hot-flow or cold-flow gas-stand. Since heat transfer situations vary for on-engine turbochargers, the maps have to be shifted and corrected in the 1-D engine simulation, which mass and efficiency multipliers usually do for both the turbine and the compressor. The multipliers change the maps and are often different for every load point. Particularly, the efficiency multiplier is different for every heat transfer situation on the turbocharger. The heat transfer leads to a deviation from turbocharger performance maps, and increased complexity of the turbocharged engine simulation. Turbochargers operate under different heat transfer situations while they are installed on the engines.

    The main objectives of this thesis are:

    • heat transfer modeling of a turbocharger to quantify and qualify heat transfer mechanisms,
    • improving turbocharged engine simulation by including heat transfer in the turbocharger,
    • assessing the use of two different turbocharger performance maps concerning the heat transfer situation (cold-measured and hot-measured turbocharger performance maps) in the simulation of a measured turbocharged engine,
    • prediction of turbocharger walls’ temperatures and their effects on the turbocharger performance on different heat transfer situations.

    Experimental investigation has been performed on a water-oil-cooled turbocharger, which was installed on a 2-liter GDI engine for different load points of the engine and different heat transfer situations on the turbocharger by using insulators, an extra cooling fan, radiation shields and water-cooling settings. In addition, several thermocouples have been used on accessible surfaces of the turbocharger to calculate external heat transfers.

    Based on the heat transfer analysis of the turbocharger, the internal heat transfer from the bearing housing to the compressor significantly affects the compressor. However, the internal heat transfer from the turbine to the bearing housing and the external heat transfer of the turbine housing mainly influence the turbine. The external heat transfers of the compressor housing and the bearing housing, and the frictional power do not play an important role in the heat transfer analysis of the turbocharger.

    The effect of the extra cooling fan on the energy balance of the turbocharger is significant. However, the effect of the water is more significant on the external heat transfer of the bearing housing and the internal heat transfer from the bearing housing to the compressor. It seems the radiation shield between the turbine and the compressor has no significant effect on the energy balance of the turbocharger.

    The present study shows that the heat transfer in the turbocharger is very crucial to take into account in the engine simulations. This improves simulation predictability in terms of getting the compressor efficiency multiplier equal to one and turbine efficiency multiplier closer to one, and achieving turbine outlet temperature close to the measurement. Moreover, the compressor outlet temperature becomes equal to the measurement without correcting the map.

    The heat transfer situation during the measurement of the turbocharger performance influences the amount of simulated heat flow to the compressor. The heat transfer situation may be defined by the turbine inlet temperature, oil heat flux and water heat flux. However, the heat transfer situation on the turbine makes a difference on the required turbine efficiency multiplier, rather than the amount of turbine heat flow. It seems the turbine heat flow is a stronger function of available energy into the turbine. Of great interest is the fact that different heat situations on the turbocharger do not considerably influence the pressure ratio of the compressor. The turbine and compressor efficiencies are the most important parameters that are affected by that.

    The component temperatures of the turbocharger influence the working fluid temperatures. Additionally, the turbocharger wall temperatures are predictable from the experiment. This prediction enables increased precision in engine simulations for future works in transient operations.

  • 245.
    Aghaali, Habib
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Ångstrom, Hans-Erik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Demonstration of Air-Fuel Ratio Role in One-Stage Turbocompound Diesel Engines2013Inngår i: SAE Technical Papers, 2013, Vol. 11Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A large portion of fuel energy is wasted through the exhaust of internal combustion engines. Turbocompound can, however, recover part of this wasted heat. The energy recovery depends on the turbine efficiency and mass flow as well as the exhaust gas state and properties such as pressure, temperature and specific heat capacity.

    The main parameter influencing the turbocompound energy recovery is the exhaust gas pressure which leads to higher pumping loss of the engine and consequently lower engine crankshaft power. Each air-fuel equivalence ratio (λ) gives different engine power, exhaust gas temperature and pressure. Decreasing λ toward 1 in a Diesel engine results in higher exhaust gas temperatures of the engine.  λ can be varied by changing the intake air pressure or the amount of injected fuel which changes the available energy into the turbine. Thus, there is a compromise between gross engine power, created pumping power, recovered turbocompound power and consumed compressor power.

    In this study, the effects of different λ values and exhaust back-pressure have been investigated on the efficiency of a heavy-duty Diesel engine equipped with a single-stage electric turbocompounding. A one-dimensional gas dynamics model of a turbocharged engine was utilized that was validated against measurements at different load points. Two configurations of turbocompound engine were made. In one configuration an electric turbocharger was used and the amount of fuel was varied with constant intake air pressure. In another configuration the turbocharger turbine and compressor were disconnected to be able to control the turbine speed and the compressor speed independently; then the compressor pressure ratio was varied with constant engine fuelling and the exhaust back-pressure was optimized for each compressor pressure ratio.

    At each constant turbine efficiency there is a linear relation between the optimum exhaust back-pressure and ideally expanded cylinder pressure until bottom dead center with closed exhaust valves. There is an optimum λ for the turbocharged engine with regard to the fuel consumption. In the turbocompound engine, this will be moved to a richer λ that gives the best total specific fuel consumption; however, the results of this study indicates that turbocompound engine efficiency is relatively insensitive to the air-fuel ratio.

  • 246.
    Aghaali, Habib
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik. KTH, Skolan för industriell teknik och management (ITM), Centra, Competence Center for Gas Exchange (CCGEx).
    Ångström, Hans-Erik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik. KTH, Skolan för industriell teknik och management (ITM), Centra, Competence Center for Gas Exchange (CCGEx).
    A review of turbocompounding as a waste heat recovery system for internal combustion engines2015Inngår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 49, s. 813-824Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Internal combustion engines waste a large amount of fuel energy through their exhausts. Various technologies have been developed for waste heat recovery such as turbocompounds, Rankine bottoming cycles, and thermoelectric generators that reduce fuel consumption and CO2 emissions. Turbocompounding is still not widely applied to vehicular use despite the improved fuel economy, lower cost, volume, and complexity higher exhaust gas recirculation driving capability and improved transient response. This paper comprehensively reviews the latest developments and research on turbocompounding to discover important variables and provide insights into the implementation of a high-efficiency turbocompound engine. Attention should be paid to the optimization of turbocompound engines and their configurations because the major drawback of this technology is additional exhaust back-pressure, which leads to higher pumping loss in the engines. Applying different technologies and concepts on turbocompound engines makes the exhaust energy recovery more efficient and provides more freedom in the design and optimization of the engines. Turbine efficiency plays an important role in the recovery of the wasted heat so turbine design is a crucial issue in turbocompounding. In addition, variability in geometry and rotational speed of power turbines allows for more efficient turbocompound engines in different operating conditions. The conclusion drawn from this review is that turbocompounding is a promising technology for reducing fuel consumption in the coming decades in both light- and heavy-duty engines.

  • 247.
    Aghaali, Habib
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Ångström, Hans-Erik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Effects of Effective Flow Areas of Exhaust Valves on a Turbocompound Diesel Engine Combined With Divided Exhaust Period2014Inngår i: Proceedings from the FISITA 2014 World Automotive Congress, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Research and /or Engineering Questions/Objective: Exhaust gas energy recovery in internal combustion engines is one of the key challenges in the future developments. The objective of this study is to reveal the fuel-saving potential of a turbocompound Diesel engine combined with divided exhaust period (DEP). The exhaust flow is provided for two different manifolds via separate valves, blowdown and scavenging, at different timings. The main challenge in this combination is choked flow through the exhaust valves due to the restricted effective flow areas. Therefore, the effects of enlarged effective flow areas of the exhaust valves are studied.

    Methodology: A commercial 1D gas dynamics code, GT-POWER, was used to simulate a turbocharged Diesel engine which was validated against measurements. Then the turbocharged engine model was modified to a turbocompound engine with DEP. Using statistical analysis in the simulation (design of experiment), the performance of this engine was studied at different sizes, lift curves and timings of the exhaust valves and turbine swallowing capacity.

    Results: In the paper the effects of the effective flow areas of the exhaust valves are presented on the break specific fuel consumption, pumping mean effective pressure and the turbine energy recovery by increasing the valve size and modifying valve lift curve to fast opening and closing. This has been done in a low engine speed and full load. The main finding is that the flow characteristics of the exhaust valves in the turbocompound DEP engine are very important for gaining the full efficiency benefit of the DEP concept.  The turbocompound DEP engine with modified valve lift shape of the exhaust valves could improve the overall brake specific fuel consumption by 3.44% in which 0.64% of the improvement is due to the valve lift curve. Modified valve lift curves contribute mainly in decreasing the period of choked flow through the exhaust valves.

    Limitations of this study: The simulations were not validated against measurements; however, the mechanical and geometrical limitations were tried to keep realistic when manipulating the valve flow area events.

    What does the paper offer that is new in the field in comparison to other works of the author: In addition to the novelty of the engine architecture that combines turbocompound with DEP, the statistical analysis and comparison presented in this paper is new especially with demonstrating the importance of crank angle coupled flow characteristics of the valves.

    Conclusion: To achieve full fuel-saving potential of turbocompound DEP engines, the flow characteristics of the exhaust valves must be considered. The effective flow areas of the exhaust valves play important roles in the choked flow through the valves, the pumping work and the brake specific fuel consumption of the engine.

  • 248.
    Aghaali, Habib
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Ångström, Hans-Erik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Externally divided exhaust period on a turbocompound engine for fuel-saving2014Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    To improve exhaust heat utilization of a turbocharged engine, divided exhaust period (DEP) and turbocompound are integrated. The DEP concept decreases pumping loss created by the turbocompound. In the DEP concept the exhaust flow is divided between two different exhaust manifolds, blowdown and scavenging. One of the two exhaust valves on each engine cylinder is opened to the blowdown manifold at the first phase of exhaust stroke and the other valve is opened to the scavenging manifold at the later phase of exhaust stroke. This leads to lower exhaust back pressure and pumping loss. The combination of turbocompound engine with DEP has been examined previously and the result showed that this combination reduces the fuel consumption in low engine speeds and deteriorates it in high engine speeds. The main restriction of this combination was the low effective flow areas of the exhaust valves at high engine speeds.

    To overcome this restriction and increase the effective flow areas of the exhaust valves, DEP is employed externally on the exhaust manifold instead of engine exhaust valves. In externally DEP (ExDEP), both exhaust valves will be opened and closed similar to the corresponding turbocharged engine and the exhaust flow is divided by flow splits on the exhaust manifold. Two valves on the outlet ports of each flow split are added. One of them is a non-return valve (check valve) and the other one is synchronized with the cam shaft.

    In this study, the fuel-saving potential of ExDEP is analysed on the turbocompound engine at different engine speeds and loads and compared with the corresponding turbocharged engine, turbocompound engine and turbocompound DEP engine equipped. The results show that ExDEP has a great fuel-saving potential in almost all load points.

    ExDEP concept, itself, is a novel concept that there is no available literature about it. Moreover, combination of this new gas exchange system with turbocompound engines is an innovative extension of combined turbocompound DEP engines.

  • 249.
    Aghaali, Habib
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Ångström, Hans-Erik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Improving Turbocharged Engine Simulation by Including Heat Transfer in the Turbocharger2012Inngår i: 2012 SAE International, SAE international , 2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Engine simulation based on one-dimensional gas dynamics is well suited for integration of all aspects arising in engine and power-train developments. Commonly used turbocharger performance maps in engine simulation are measured in non-pulsating flow and without taking into account the heat transfer. Since on-engine turbochargers are exposed to pulsating flow and varying heat transfer situations, the maps in the engine simulation, i.e. GT-POWER, have to be shifted and corrected which are usually done by mass and efficiency multipliers for both turbine and compressor. The multipliers change the maps and are often different for every load point. Particularly, the efficiency multiplier is different for every heat transfer situation on the turbocharger. The aim of this paper is to include the heat transfer of the turbocharger in the engine simulation and consequently to reduce the use of efficiency multiplier for both the turbine and compressor. A set of experiment has been designed and performed on a water-oil-cooled turbocharger, which was installed on a 2 liter GDI engine with variable valve timing, for different load points of the engine and different conditions of heat transfer in the turbocharger. The experiments were the base to simulate heat transfer on the turbocharger, by adding a heat sink before the turbine and a heat source after the compressor. The efficiency multiplier of the turbine cannot compensate for all heat transfer in the turbine, so it is needed to put out heat from the turbine in addition to the using of efficiency multiplier. Results of this study show that including heat transfer of turbocharger in engine simulation enables to decrease the use of turbine efficiency multiplier and eliminate the use of compressor efficiency multiplier to correctly calculate the measured gas temperatures after turbine and compressor.

  • 250.
    Aghaali, Habib
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Ångström, Hans-Erik
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Förbränningsmotorteknik.
    Performance Sensitivity to Exhaust Valves and Turbine Parameters on a Turbocompound Engine with Divided Exhaust Period2014Inngår i: SAE International Journal of Engines, ISSN 1946-3936, E-ISSN 1946-3944, Vol. 7, nr 4, s. 1722-1733Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Turbocompound can utilize part of the exhaust energy on internal combustion engines; however, it increases exhaust back pressure, and pumping loss.  To avoid such drawbacks, divided exhaust period (DEP) technology is combined with the turbocompound engine. In the DEP concept the exhaust flow is divided between two different exhaust manifolds, blowdown and scavenging, with different valve timings. This leads to lower exhaust back pressure and improves engine performance.

    Combining turbocompound engine with DEP has been theoretically investigated previously and shown that this reduces the fuel consumption and there is a compromise between the turbine energy recovery and the pumping work in the engine optimization. However, the sensitivity of the engine performance has not been investigated for all relevant parameters. The main aim of this study is to analyze the sensitivity of this engine architecture in terms of break specific fuel consumption to different parameters concerning the gas exchange such as blowdown valve timing, scavenging valve timing, blowdown valve size, scavenging valve size, discharge coefficients of blowdown and scavenging ports, turbine efficiency, turbine size and power transmission efficiency. This study presents the sensitivity analysis of the turbocompound DEP engine to these parameters and defines a set of important parameters that should be examined in experimental studies.

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