Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A re-examination of filter-based stabilization for spectral-element methods
KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, Centres, SeRC - Swedish e-Science Research Centre. Swedish e-Science Research Center, SeRC.
KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, Centres, SeRC - Swedish e-Science Research Centre. Swedish e-Science Research Center, SeRC.
KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, Centres, SeRC - Swedish e-Science Research Centre. Swedish e-Science Research Center, SeRC.
2017 (English)Report (Other academic)
Place, publisher, year, edition, pages
2017. , p. 19
Series
TRITA-MEK, ISSN 0348-467X
National Category
Mechanical Engineering
Research subject
Engineering Mechanics
Identifiers
URN: urn:nbn:se:kth:diva-217972ISRN: KTH/MEK/TR-17/15-SEISBN: 978-91-7729-591-4 (print)OAI: oai:DiVA.org:kth-217972DiVA, id: diva2:1158465
Note

QC 20171121

Available from: 2017-11-20 Created: 2017-11-20 Last updated: 2017-11-21Bibliographically approved
In thesis
1. Boundary layers over wing sections
Open this publication in new window or tab >>Boundary layers over wing sections
2017 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The understanding of developing boundary layers over wings is an important topic from the perspective of industrial applications. An increased understanding would be consequential not only for achieving higher fuel efficiency but also in the design of aircraft control strategies. With these aims in mind, the current work aims to further the understanding of developing boundary layer over wingsections. The study is performed with two particular perspectives in mind -unsteady aerodynamic effects in a pitching airfoil and turbulent boundary layerstructure in non-equilibrium boundary layers over a stationary airfoil.The boundary layer evolution in unsteady natural laminar flow airfoils undergoing small-amplitude pitch-oscillations is investigated. For high Reynolds numbers the origins of the non-linear unsteady aerodynamic response of laminar airfoils is explained on the basis of quasi-steady assumptions. Temporal nonlinearitiesin aerodynamic forces are shown to be inherently linked to thenon-linearities of static aerodynamic force coefficients and that a simple phaselagconcept can model the observed non-linear unsteady response. On the other hand at lower Reynolds numbers, when there exists an unstable leading edgelaminar separation bubble, the unsteady response is dynamically rich and changes in boundary layer characteristics can be abrupt. Such quasi-steadyphase-lag concepts are no longer appropriate to explain the unsteady flow physics in such a case. For the case of stationary airfoils, flow statistics for flow around an airfoil at two different Reynolds numbers are compared to assess Reynolds number effects in non-equilibrium flows. Pressure gradient effects found to be stronger at low Reynolds numbers, leading to higher energy in the larger structures present  in the outer part of the turbulent boundary layer.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2017. p. 25
Series
TRITA-MEK, ISSN 0348-467X ; 2017:15
National Category
Fluid Mechanics and Acoustics Aerospace Engineering
Research subject
Engineering Mechanics
Identifiers
urn:nbn:se:kth:diva-217984 (URN)978-91-7729-591-4 (ISBN)
Presentation
2017-12-13, D3, Lindstedtsvägen 5, KTH, Stockholm, 15:15 (English)
Opponent
Supervisors
Note

QC 20171121

Available from: 2017-11-21 Created: 2017-11-20 Last updated: 2017-11-22Bibliographically approved

Open Access in DiVA

negi_reexamination_filter_based_stabilization_sem.pdf(1850 kB)57 downloads
File information
File name FULLTEXT01.pdfFile size 1850 kBChecksum SHA-512
05e00be0643e3431f6a2a9c0fb4a154d32a51827c82c822f156491c7bf31a88a549414bf332f478823e4b2d5fcfba0c2afa5bc1cba439f68a3770fd5e7641090
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Negi, PrabalSchlatter, PhilippHenningson, Dan
By organisation
Stability, Transition and ControlLinné Flow Center, FLOWSeRC - Swedish e-Science Research Centre
Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 57 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 621 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf