Abstract
The flow over an open aircraft bay is often represented in a wind tunnel with a cavity. In flight, this flow is unconfined, though in experiments, the cavity is surrounded by wind tunnel walls. If untreated, wind tunnel wall effects can lead to significant distortions of cavity acoustics in subsonic flows. To understand and mitigate these cavity–tunnel interactions, a parametric approach was taken for flow over an L/D = 7 cavity at Mach numbers 0.6–0.8. With solid tunnel walls, a dominant cavity tone was observed, likely due to an interaction with a tunnel duct mode. An acoustic liner opposite the cavity decreased the amplitude of the dominant mode and its harmonics, a result observed by previous researchers. Acoustic dampeners were also placed in the tunnel sidewalls, which further decreased the dominant mode amplitudes and peak amplitudes associated with nonlinear interactions between cavity modes. This indicates that cavity resonance can be altered by tunnel sidewalls and that spanwise coupling should be addressed when conducting subsonic cavity experiments. Though mechanisms for dominant modes and nonlinear interactions likely exist in unconfined cavity flows, these effects can be amplified by the wind tunnel walls.
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Notes
The theory of Alvarez and Kerschen (2005), which modeled the cavity shear layer as a vortex sheet and predicted cavity mode growth rates with eigenmode analysis, was not employed here.
References
Alvarez JO, Kerschen EJ (2005) Influence of wind tunnel walls on cavity acoustic resonances. AIAA paper, 2804
Alvarez JO, Kerschen EJ, Tumin A (2004) A theoretical model for cavity acoustic resonances in subsonic flow. AIAA, 2845
Arunajatesan S, Barone MF, Wagner JL, Casper KM, Beresh SJ (2014) Joint experimental/computational investigation into the effects of finite width on transonic cavity flow. AIAA paper, 3027
ASTM C423 (2009) Standard test method for sound absorption and sound absorption coefficients by the reverberation room method. ASTM, Philadelphia, USA
Beresh SJ, Wagner JL, Pruett BOM, Henfling JF, Spillers RW (2014) Supersonic flow over a finite-width rectangular cavity. AIAA J 53(2):296–310
Brès GA, Colonius T (2008) Three-dimensional instabilities in compressible flow over open cavities. J Fluid Mech 599:309–339
Cattafesta LN, Song Q, Williams DR, Rowley CW, Alvi FS (2008) Active control of flow-induced cavity oscillations. Prog Aerosp Sci 44:479–502
Debiasi M, Little J, Malone J, Samimy M, Yan P, Özbay H, Myatt J (2004) An experimental study of subsonic cavity flow–physical understanding and control. AIAA paper, 2123
Dix RE, Bauer RC (2000) Experimental and predicted acoustic amplitudes in a rectangular cavity. AIAA paper, 0472
Dix RE, Bauer RC (2000) Experimental and theoretical study of cavity acoustics. AEDC-TR-99-4, May 2000
Goethert BH (1961) Transonic wind tunnel testing. Dover, New York
Goethert BH (1956) Physical aspects of three-dimensional wave reflections in transonic wind tunnels at Mach number 1.20 (perforated, slotted and combined slotted-perforated walls). AEDC-TR-55-45
Heller HH, Bliss DB (1975) The physical mechanism of flow induced pressure fluctuations in cavities and concepts for suppression. AIAA paper, 75–491
Kegerise MA (1999) An experimental investigation of flow induced cavity oscillations. Ph.D. Thesis, Department of Mechanical Engineering, Syracuse University, New York, USA
Kegerise MA, Spina EF, Garg S, Cattafesta LN (2005) Mode-switching and nonlinear effects in compressible flow over a cavity. Phys Fluids 16(3):678–687
Krishnamurty K (1955) Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces. NACA TN 3487
Larchevêque L, Sagaut P, Labbé O (2007) Large-Eddy simulation of a subsonic cavity flow including asymmetric three-dimensional effects. J Fluid Mech 577:105–126
McCanless GF, Boone JR (1974) Noise reduction in transonic wind tunnels. J Acoust Soc Am 56(5):1501–1510
McGregor OW, White RA (1970) Drag of rectangular cavities in supersonic and transonic flow including the effects of cavity resonance. AIAA J 8(11):1959–1964
Murray N (2006) Flowfield dynamics in subsonic cavity flows. Ph.D. Thesis, Department of Aeroacoustics, University of Mississippi, Oxford, USA
Murray N, Sallstrom E, Ukeiley L (2009) Properties of subsonic open cavity flow fields. Phys Fluids 21(9):095103
Norton MP, Karczub DG (2003) Fundamentals of noise and vibration analysis for engineers. Cambridge University Press, Cambridge, p 316
Rockwell D, Knisely C (1980) Observations of the three-dimensional nature of unstable flow past a cavity. Phys Fluids 23(3):425–431
Rockwell D, Naudascher E (1978) Review-self sustaining oscillations of flow past cavities. J Fluids Eng 100:152–165
Rockwell D, Naudascher E (1979) Self-sustained oscillations of impinging free shear layers. Annu Rev Fluid Mech 11:67–94
Rossiter JE (1964) Wind-tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. Aeronautical Research Council Reports and Memoranda, October 1964
Rowley CW, Williams DR, Colonius T, Murray RM, MacMartin DG, Fabris D (2002) Model-based control of cavity oscillations, part II: system identification and analysis. AIAA paper, 0972
Rowley CW, Williams DR (2006) Dynamics and control of high-reynolds-number flow over open cavities. Annu Rev Fluid Mech 38:251–276
Rowley CW, Williams DR, Colonius T, Murray RM, Macmynowski DG (2006) Linear models for control of cavity flow oscillations. J Fluid Mech 547:317–330
Song Q (2008) Closed-loop control of flow-induced cavity oscillations. Ph.D. Thesis, Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, USA
Stallings RL, Wilcox FJ (1987) Experimental cavity pressure distributions at supersonic speeds. NASA technical paper 2683, June 1987
Tracy MB, Plentovich EB (1997) Cavity unsteady-pressure measurements at subsonic and transonic speeds. NASA technical paper 3669, December 1997
Ukeiley LS, Murray NE (2005) Velocity and surface pressure measurements in an open cavity. Exp Fluids 38:656–671
Varner MW (1975) Noise generation in transonic tunnels. AIAA J 13(11):1417–1418
Wagner JL, Casper KM, Beresh SJ, Hunter PS, Spillers, RW, Henfling JF, Mayes RL (2013) Experimental investigation of fluid-structure interactions in compressible cavity flows. AIAA paper, 3172
Williams DR, Fabris D, Morrow J (2000) Experiments on controlling multiple acoustic modes in cavities. AIAA paper, 1903
Zhang K, Naguib AM (2011) Effect of finite cavity width on flow oscillation in a low-mach-number cavity flow. Exp Fluids 51(5):1209–1229
Zhuang N, Alvi FS, Alkislar MB, Shih C (2006) supersonic cavity flows and their control. AIAA J 44(9):2118–2128
Acknowledgments
The authors thank Srini Arunajatesen and Matthew Barone for very helpful discussions on cavity–tunnel interactions. They are also grateful to Tom Grasser who designed the acoustic liner and cavity hardware. Finally, the authors thank Professor Lawrence Ukeiley of the University of Florida and Professor Louis Cattafesta of Florida State University for sharing their significant insight and experience on mitigating wind tunnel modes and their suggestions for acoustic liner design and evaluation. This work is supported by Sandia National Laboratories and the United States Department of Energy. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
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Wagner, J.L., Casper, K.M., Beresh, S.J. et al. Mitigation of wind tunnel wall interactions in subsonic cavity flows. Exp Fluids 56, 59 (2015). https://doi.org/10.1007/s00348-015-1924-8
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DOI: https://doi.org/10.1007/s00348-015-1924-8