Confinement effects on regular-irregular transition in shock wave-boundary-layer interactions
File(s)
Published version
Author(s)
Grossman, Ilan
Bruce, P
Type
Journal Article
Abstract
An oblique shock wave is generated in a Mach 2 flow at a flow deflection angle of 12∘ . The resulting shock-wave–boundary-layer interaction (SWBLI) at the tunnel wall is observed. A novel traversable shock generator allows the position of the SWBLI to be varied relative to a downstream expansion fan. The relationship between the SWBLI, the expansion fan and the wind tunnel arrangement is studied. Schlieren photography, surface oil flow visualisation, particle image velocimetry and high-spatial-resolution wall pressure measurements are used to investigate the flow. It is observed that stream-normal movement of the shock generator downwards (towards the floor and hence the point of shock reflection) is accompanied by (1) growth in the streamwise extent of the shock-induced boundary layer separation, (2) upstream movement of the shock-induced separation point while the reattachment point remains nearly fixed, (3) an increase in separation shock strength and (4) transition between regular and irregular (Mach) reflection without an increase in incident shock strength. The role of free interaction theory in defining the separation shock angle is considered and shown to be consistent with the present measurements over a short streamwise extent. An SWBLI representation is proposed and reasoned which explains the apparent increase in separation shock strength that occurs without an increase in incident shock strength.
Date Issued
2018-10-25
Date Acceptance
2018-06-30
Citation
Journal of Fluid Mechanics, 2018, 853 (1), pp.171-204
ISSN
0022-1120
Publisher
Cambridge University Press
Start Page
171
End Page
204
Journal / Book Title
Journal of Fluid Mechanics
Volume
853
Issue
1
Copyright Statement
© 2018 Cambridge University Press
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Identifier
https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/confinement-effects-on-regularirregular-transition-in-shockwaveboundarylayer-interactions/39112DEF1944126CEAD09B304666EAAB
Subjects
Science & Technology
Technology
Physical Sciences
Mechanics
Physics, Fluids & Plasmas
Physics
boundary layer separation
high-speed flow
shock waves
LOW-FREQUENCY UNSTEADINESS
MACH REFLECTION
STEADY FLOWS
INDUCED SEPARATION
RECONSIDERATION
CRITERION
PATTERNS
MOTIONS
INLETS
Fluids & Plasmas
01 Mathematical Sciences
09 Engineering
Publication Status
Published
Date Publish Online
2018-08-22