Large-eddy simulation of low-frequency unsteadiness in a turbulent shock-induced separation bubble
Large-eddy simulation of low-frequency unsteadiness in a turbulent shock-induced separation bubble
The need for better understanding of the low-frequency unsteadiness observed in shock wave/turbulent boundary layer interactions has been driving research in this area for several decades. We present here a large-eddy simulation investigation of the interaction between an impinging oblique shock and a Mach 2.3 turbulent boundary layer. Contrary to past large-eddy simulation investigations on shock/turbulent boundary layer interactions, we have used an inflow technique which does not introduce any energetically significant low frequencies into the domain, hence avoiding possible interference with the shock/boundary layer interaction system. The large-eddy simulation has been run for much longer times than previous computational studies making a Fourier analysis of the low frequency possible. The broadband and energetic low-frequency component found in the interaction is in excellent agreement with the experimental findings. Furthermore, a linear stability analysis of the mean flow was performed and a stationary unstable global mode was found. The long-run large-eddy simulation data were analyzed and a phase change in the wall pressure fluctuations was related to the global-mode structure, leading to a possible driving mechanism for the observed low-frequency motions.
Shock boundary layer interaction, global mode, compressible turbulence, les, low-frequency unsteadiness, separation bubble, digital filter, inflow turbulence
79-107
Touber, Emile
0d715527-5254-488a-8ad2-a4829eb89936
Sandham, Neil D.
0024d8cd-c788-4811-a470-57934fbdcf97
June 2009
Touber, Emile
0d715527-5254-488a-8ad2-a4829eb89936
Sandham, Neil D.
0024d8cd-c788-4811-a470-57934fbdcf97
Touber, Emile and Sandham, Neil D.
(2009)
Large-eddy simulation of low-frequency unsteadiness in a turbulent shock-induced separation bubble.
Theoretical and Computational Fluid Dynamics, 23 (2), .
(doi:10.1007/s00162-009-0103-z).
Abstract
The need for better understanding of the low-frequency unsteadiness observed in shock wave/turbulent boundary layer interactions has been driving research in this area for several decades. We present here a large-eddy simulation investigation of the interaction between an impinging oblique shock and a Mach 2.3 turbulent boundary layer. Contrary to past large-eddy simulation investigations on shock/turbulent boundary layer interactions, we have used an inflow technique which does not introduce any energetically significant low frequencies into the domain, hence avoiding possible interference with the shock/boundary layer interaction system. The large-eddy simulation has been run for much longer times than previous computational studies making a Fourier analysis of the low frequency possible. The broadband and energetic low-frequency component found in the interaction is in excellent agreement with the experimental findings. Furthermore, a linear stability analysis of the mean flow was performed and a stationary unstable global mode was found. The long-run large-eddy simulation data were analyzed and a phase change in the wall pressure fluctuations was related to the global-mode structure, leading to a possible driving mechanism for the observed low-frequency motions.
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Published date: June 2009
Keywords:
Shock boundary layer interaction, global mode, compressible turbulence, les, low-frequency unsteadiness, separation bubble, digital filter, inflow turbulence
Organisations:
Aerodynamics & Flight Mechanics
Identifiers
Local EPrints ID: 66710
URI: http://eprints.soton.ac.uk/id/eprint/66710
ISSN: 0935-4964
PURE UUID: 56182a98-d476-4887-86fa-c95a57a467bf
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Date deposited: 13 Jul 2009
Last modified: 14 Mar 2024 02:42
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Author:
Emile Touber
Author:
Neil D. Sandham
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