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Experiments in Fluids

, 56:152 | Cite as

Visualization of wave propagation within a supersonic two-dimensional cavity by digital streak schlieren

  • Vikram Sridhar
  • Harald KleineEmail author
  • Sudhir L. Gai
Research Article

Abstract

Optical measurements were carried out in planar two-dimensional open shallow cavities in order to determine how the flow field inside the cavity changes if the length-to-depth ratio of the cavity and the conditions of the boundary layer at the cavity leading edge are varied. The main challenge in this configuration, namely the fact that there are often no clearly identifiable wave fronts in the flow within the cavity, was overcome by applying a digital streak schlieren technique in combination with time-resolved high-speed flow visualizations. Using this approach, one can identify the propagation of waves within the cavity which allows one to determine the frequencies of flow oscillations inside the cavity entirely by optical means. The results from these measurements showed excellent agreement with independently conducted pressure measurements, simulations and analytical predictions. The applied technique also provides a measurement for the convective flow velocity within the cavity, for which different values can be found in the literature. The paper presents the results obtained for a Mach 2 supersonic flow over shallow rectangular open cavities with length-to-depth ratios of 3, 5, 6 and 8.

Keywords

Shear Layer Wave Front Boundary Layer Thickness Free Stream Convective Velocity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

The authors would like to acknowledge the outstanding technical support provided by the Mechanical Workshop of the School of Engineering and IT, UNSW Canberra, and in particular the assistance given by Mr. Michael Jones.

References

  1. Ahuja K, Mendoza J (1995) Effects of cavity dimensions, boundary layer, and temperature on cavity noise with emphasis on benchmark data to validate computational aeroacoustic codes. Technical report 4653, NASA, VirginiaGoogle Scholar
  2. Bauer R, Dix R (1991) Engineering model of unsteady flow in a cavity. Technical report AEDC-TR-91-17, Arnold Engineering Development CenterGoogle Scholar
  3. Chapman DR, Kuehn DM, Larson HK (1957) Investigation of separated flows in supersonic and subsonic streams with emphasis on the effect of transition. Technical report 1356, NACAGoogle Scholar
  4. Fuller PWW (1979) High speed photography in ballistics. In: Proceedings of 8th international congress on instrumentation in aerospace simulation facilities, Institute of Electrical and Electronic Engineers, pp 112–123Google Scholar
  5. Gai SL, Kleine H, Neely AJ (2015) Supersonic flow over a shallow open rectangular cavity. J Aircr 52(2):609–616CrossRefGoogle Scholar
  6. Gloerfelt X, Bailly C, Juve D (2003) Direct computation of the noise radiated by a subsonic cavity flow and application of integral methods. J Sound Vib 266:119–146CrossRefGoogle Scholar
  7. Handa T, Miyachi H, Kakuno H, Ozaki T (2012) Generation and propagation of pressure waves in supersonic deep cavity flows. Exp Fluids 53:1855–1866CrossRefGoogle Scholar
  8. Hankey W, Shang J (1980) Analyses of pressure oscillations in an open cavity. AIAA J 18(8):892–898MathSciNetCrossRefzbMATHGoogle Scholar
  9. Hargather MJ, Lawson MJ, Settles GS (2011) Seedless velocimetry measurements by schlieren image velocimetry. AIAA J 49(3):611–620CrossRefGoogle Scholar
  10. Hargather MJ, Settles GS, Gogineni S (2013) Optical diagnostics for characterizing a transitional shear layer over a supersonic cavity. AIAA J 51(12):2977–2982CrossRefGoogle Scholar
  11. Heller H, Holmes D, Covert E (1971) Flow-induced pressure oscillations in shallow cavities. J Sound Vib 18(4):547–553CrossRefGoogle Scholar
  12. Heller HH, Bliss DB (1975) Aerodynamically induced resonance in rectangular cavities—Physical Mechanisms and Supression Concepts. Technical report AFFDL-TR-74-133, Wright-Patterson Air Force BaseGoogle Scholar
  13. Katayama AS (1994) Visualization techniques for temporally acquired sequences of images. US Patent No. 5294978Google Scholar
  14. Kleine H (2010) Filming the invisible-time-resolved visualisation of compressible flows. Eur Phys J Spec Top 182:3–34CrossRefGoogle Scholar
  15. Krishnamurthy K (1955) Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces. Technical report 3487, NACAGoogle Scholar
  16. Mohri S, Hillier R (2011) Computational and experimental study of supersonic flow over axisymmetric cavities. Shock Waves 21(3):175–191CrossRefGoogle Scholar
  17. Murray R, Elliot G (2001) Characteristics of compressible shear layer over a cavity. AIAA J 39(5):846–856CrossRefGoogle Scholar
  18. Oster D, Wygnanski I (1982) The forced mixing layer between parallel streams. J Fluid Mech 123:91–130CrossRefGoogle Scholar
  19. Papamoschou D, Roshko A (1988) The compressible turbulent shear layer: an experimental study. J Fluid Mech 197:453–477CrossRefGoogle Scholar
  20. Perng S, Dolling D (2001) Suppression of pressure oscillations in high-mach-number, turbulent cavity flow. J Aircr 38(2):248–256CrossRefGoogle Scholar
  21. Rona A (2006) Self-excited supersonic cavity flow instabilities as aerodynamic noise sources. Int J Aeroacoust 5(4):335–360CrossRefGoogle Scholar
  22. Rossiter J (1964) Wind tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. Technical report 3438, Ministry of AviationGoogle Scholar
  23. Schardin H (1942) Schlierenmethoden und ihre Anwendungen. Ergebnisse der exakten Naturwissenschaften 20:303–439CrossRefGoogle Scholar
  24. Settles GS (2001) Schlieren and shadowgraph techniques: visualizing phenomena in transparent media. Springer, BerlinCrossRefGoogle Scholar
  25. Smits AJ, Dussauge JP (2005) Turbulent shear layers in supersonic flow, 2nd edn. Springer, BerlinGoogle Scholar
  26. Sridhar V, Kleine H, Gai SL (2013) Unsteady flow patterns in supersonic cavity flows. In: Proceedings of 30th international congress high-speed imaging and photonics. University of the Witwatersrand, Johannesburg, South Africa, pp 199–204Google Scholar
  27. Sridhar V (2014) Computational and experimental investigation of supersonic two-dimensional and axi-symmetric shallow open cavities. Ph.D. thesis, The University of New South Wales, AustraliaGoogle Scholar
  28. Tam CJ, Orkwis PD, Disimile PJ (1996) Algebraic turbulence model simulations of supersonic open cavity flow physics. AIAA J 34(11):2255–2260CrossRefGoogle Scholar
  29. Ünalmis O, Clemens N, Dolling D (2001) Experimental study of shear-layer/acoustics coupling in Mach 5 cavity flow. AIAA J 39(2):242–252CrossRefGoogle Scholar
  30. Ünalmis O, Clemens N, Dolling D (2004) Cavity oscillation mechanisms in high-speed flows. AIAA J 42(10):2035–2041CrossRefGoogle Scholar
  31. Zhang X, Edwards J (1990) An investigation of supersonic oscillatory cavity flows driven by thick shear layers. Aeronaut J 94(12):355–364Google Scholar
  32. Zhang X (1995) Compressible cavity flow oscillation due to shear layer instabilities and pressure feedback. AIAA J 33(8):1404–1411CrossRefzbMATHGoogle Scholar
  33. Zhuang N, Alvi F, Alkislar M, Shih C (2006) Supersonic cavity flows and their control. AIAA J 44(9):2118–2128CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.University of New South Wales at Australian Defence Force AcademyCanberraAustralia

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