Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-26T08:21:46.936Z Has data issue: false hasContentIssue false

Physics of unsteady blunt-fin-induced shock wave/turbulent boundary layer interactions

Published online by Cambridge University Press:  26 April 2006

Leon Brusniak
Affiliation:
Department of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin, Austin, TX 78712-1085, USA
David S. Dolling
Affiliation:
Department of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin, Austin, TX 78712-1085, USA

Abstract

Fluctuating wall-pressure measurements have been made on the centreline upstream of a blunt fin in a Mach 5 turbulent boundary layer. By examining the ensemble-averaged wall-pressure distributions for different separation shock foot positions, it has been shown that local fluctuating wall-pressure measurements are due to a distinct pressure distribution, [weierp ]i, which undergoes a stretching and flattening effect as its upstream boundary translates aperiodically between the upstream-influence and separation lines. The locations of the maxima and minima in the wall-pressure standard deviation can be accurately predicted using this distribution, providing quantitative confirmation of the model. This model also explains the observed cross-correlations and ensemble-average measurements within the interaction. Using the [weierp ]i model, wall-pressure signals from under the separated flow region were used to reproduce the position–time history of the separation shock foot. The unsteady behaviour of the primary horseshoe vortex and its relation to the unsteady separation shock is also described. The practical implications are that it may be possible to predict some of the unsteady aspects of the flowfield using mean wall-pressure distributions obtained from either computations or experiments; also, to minimize the fluctuating loads caused by the unsteadiness, flow control methods should focus on reducing the magnitude of the [weierp ]i gradient (∂[weierp ]i/∂x).

Type
Research Article
Copyright
© 1994 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bendat, J. D. & Piersol, A. G. 1986 Random Data, Analysis and Measurement Procedures, 2nd edition. John Wiley.
Brusniak, L. 1994 Physics of unsteady blunt fin-induced shock wave/ turbulent boundary layer interactions. PhD dissertation, Dept of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin.
Dolling, D. S. 1993 Fluctuating loads in shock wave/ turbulent boundary layer interaction: tutorial and update. AIAA Paper 93-0284.
Dolling, D. S. & Bogdonoff, S. M. 1981a Scaling of interactions of cylinders with supersonic turbulent boundary layers. AIAA J. 19, 655657.Google Scholar
Dolling, D. S. & Bogdonoff, S. M. 1981b An experimental investigation of the unsteady behavior of blunt fin-induced shock wave turbulent boundary layer interactions. AIAA Paper 81-1287.
Dolling, D. S. & Bogdonoff, S. M. 1982 Blunt fin-induced shock wave/ turbulent boundary layer interaction. AIAA J. 20, 16741680.Google Scholar
Dolling, D. S. & Brusniak, L. 1989 Separation shock motion in fin, cylinder, and compression ramp-induced turbulent interactions. AIAA J. 27, 734742.Google Scholar
Dolling, D. S. & Brusniak, L. 1991 Correlation of separation shock motion in a cylinder-induced interaction with pressure fluctuations under the separated region. AIAA Paper 91-0650.
Dolling, D. S., Cosad, C. D. & Bogdonoff, S. M. 1979 An examination of blunt fin-induced shock wave turbulent boundary layer interaction. AIAA Paper 79-0068.
Dolling, D. S. & Smith, D. R. 1989 Separation shock dynamics in Mach 5 turbulent interactions induced by cylinders. AIAA J. 27, 16981706.Google Scholar
Erengil, M. E. & Dolling, D. S. 1993a Effects of sweepback on unsteady separation in Mach 5 compression ramp interactions. AIAA J. 31, 302311.Google Scholar
Erengil, M. E. & Dolling, D. S. 1993b Physical causes of separation shock unsteadiness in shock wave/ turbulent boundary-layer interactions. AIAA Paper 93-3134.
Gonsalez, J. C. & Dolling, D. S. 1993 Correlation of interaction sweepback effects on the dynamics of shock-induced turbulent separation. AIAA Paper 93-0776.
Gramann, R. A. & Dolling, D. S. 1988 Detection of turbulent boundary layer separation using fluctuating wall pressure signals. AIAA Paper 88-4676.
Holden, M. S. 1986 A review of aerothermal problems associated with hypersonic flight. AIAA Paper 86-0267.
Hung, C.-M. & Buning, P. E. 1985 Simulation of blunt-fin-induced shock-wave and turbulent boundary-layer interaction. J. Fluid Mech. 154, 163185.Google Scholar
Kleifges, K. & Dolling, D. S. 1993 Control of unsteady shock-induced turbulent boundary layer separation upstream of blunt fins. AIAA Paper 93-3281.
Kussoy, M. I., Brown, J. D., Brown, J. L., Lockman, W. K. & Horstman, C. C. 1987 Fluctuations and massive separation in three-dimensional shock-wave/ boundary-layer interactions. 2nd Int. Symp. on Transport Phenomena in Turbulent Flows, Tokyo, Japan, Oct. 25–29.
Lakshmanan, B. & Tiwari, S. N. 1993 Study of supersonic intersection flowfield at modified wing-body junctions. AIAA J. 31, 877883.Google Scholar
McClure, W. B. 1992 An experimental study of the driving mechanism and control of the unsteady shock-induced turbulent separation in a Mach 5 compression corner flow. PhD dissertation, Dept of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin.
Narlo, J. C. 1986 Experimental investigation of the driving mechanisms of separation shock wave motion in interactive flows. MS thesis, Dept of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin.
Pozefsky, P., Blevins, R. D. & Laganelli, A. L. 1989 Thermo-vibro-acoustic loads and fatigue of hypersonic flight vehicle structures. AFWAL TR-89-3014.
Sun, C.-C. & Childs, M. E. 1973 A modified wall-wake velocity profile for turbulent compressible boundary layers. J. Aircraft 10, 381383.Google Scholar