Optimizing surface texture for combustion engine cylinder liners
2010 (English)Licentiate thesis, comprehensive summary (Other academic)
The Piston Ring - Cylinder Liner (PRCL) contact is the single largest contributor to frictional losses in an internal combustion (IC) engine, causing 20-40% of all mechanical losses. If these mechanical losses can be reduced by 10% then vehicle fuel efficiency could be increased by approximately 1.5-2.5%. In todays automotive industry fuel efficiency is one of the most important factors in vehicle design due to increasing concerns about energy security, increasing fuel prices and climate change. The objective of this project is to optimise the cylinder surface texture, which when referring to cylinder liners in this work means the cross-hatch grooves left by the honing process.This work focuses on simulation techniques that can be used to help optimize cylinder liner surface texture to reduce friction while at the same time minimizing oil consumption and wear. Cylinder liner surface topography is investigated with a range of measurement techniques in order to reveal all the important features of the existing surface. Different ways of characterizing surface topography based on both traditional height averaging parametersand functional parameters calculated for a range of different surface measurements are discussed. The different characterization techniques are compared to find the most appropriate way of quantitatively describing surface topographies.A full engine cycle simulation of the PRCL contact has been developed. A homogenization technique was implemented for solving the Reynolds equation. This is a two scale approach where surface roughness is treated on the local scale and surface texture plus global geometry on the global scale. A method for generating artificial surface topography based on real surface measurement data was developed. This allows for the possibility of simulating a wide range of new surface topographies in order to investigate their potential for reducing friction and minimising oil consumption and wear.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2010. , 104 p.
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Technology - Engineering mechanics
Teknikvetenskap - Teknisk mekanik
Research subject Machine Elements
IdentifiersURN: urn:nbn:se:ltu:diva-17001Local ID: 11845800-f09a-11df-8b36-000ea68e967bISBN: 978-91-7439-178-7OAI: oai:DiVA.org:ltu-17001DiVA: diva2:989994
Godkänd; 2010; 20101115 (spencer); LICENTIATSEMINARIUM Ämnesområde: Maskinelement/Machine Elements Examinator: Professor Roland Larsson, Luleå tekniska universitet Diskutant: Professor Michel Cervantes, Luleå tekniska universitet Tid: Fredag den 17 december 2010 kl 13.00 Plats: E231, Luleå tekniska universitet2016-09-292016-09-29Bibliographically approved