Advertisement

Experiments in Fluids

, Volume 42, Issue 4, pp 639–651 | Cite as

Oscillations of flow past perforated and slotted plates: attenuation via a leading-edge ramp

  • E. Celik
  • A. C. Sever
  • T. Kiwata
  • D. Rockwell
Research Article

Abstract

The present investigation aims to attenuate purely hydrodynamic, long-wavelength, self-excited oscillations of flow past a perforated or slotted plate by deflection of the inflow with a small ramp located at the leading-edge of the plate. Digital particle image velocimetry is complemented by unsteady pressure measurements to determine the underlying physics associated with attenuation of the oscillations. Irrespective of whether a perforated or slotted plate is employed, complete attenuation of the pressure fluctuations associated with the oscillation can be achieved for dimensionless deflection ratios of h/L ≥ 0.035, in which h is the height of the ramp and L is the effective plate length. The attenuation of the self-excited oscillation involves: a steady jet at the trailing-edge of the plate directed into the cavity; a lower magnitude upstream-oriented counterflow along the backside of the plate; and jet-like flows through the plate openings to satisfy the entrainment demands of the separating shear layer.

Keywords

Particle Image Velocimetry Shear Layer Perforated Plate Separate Shear Layer Plate Length 
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 gratefully acknowledge the financial support of the Office of Naval Research under Grant N00014-01 1-0606, monitored by Drs. Pat Purtell and Ron Joslin. Supplemental support, in the form of facilities and instrumentation, was from the Air Force of Scientific Research under Grant F49620-02-1-0061. The continuing advice of Dr. Ted Farabee of the Naval Surface Warfare Center, Carderock, is appreciated.

References

  1. Bruggeman JC, Velekoop JC, Van Der Knapp FGP, Keuning PJ (1991) Flow-excited resonance in a cavity covered by a grid: theory and experiments. NCA-vol 11/FED-vol 130, flow modeling, measurement and control ASME, pp 135–144Google Scholar
  2. Celik E, Rockwell D (2002) Shear layer oscillation along a perforated surface: a self-excited large-scale instability. Phys Fluids 14:4444–4448CrossRefGoogle Scholar
  3. Celik E, Rockwell D (2004) Coupled oscillations of flow along a perforated plate. Phys Fluids 16:1714–1724CrossRefGoogle Scholar
  4. Celik E, Sever AC, Rockwell D (2005) Self-sustained oscillations past perforated and slotted plates: effect of plate thickness. AIAA J 43:1850–1853Google Scholar
  5. Cicca GM, Spazzini PG, Iuso G, Malvano R, Polledro P, Onorato M (2003) PIV investigation on a backward facing step flow. Proceedings of PSFVIP-4, Chamonix, France, June 3–5Google Scholar
  6. Dickey NS, Selamet A, Ciray MS (2001) An experimental study of the impedance of perforated plates with grazing flow. J Acoust Soc Am 110:2360–2370CrossRefGoogle Scholar
  7. Howe MS (1998) Acoustics of fluid-structure interactions. Cambridge University Press, New YorkzbMATHGoogle Scholar
  8. Jing X, Sun X, Wu J, Meng K (2001) Effect of grazing flow on the acoustic impedance of an orifice. AIAA J 39:1478–1484CrossRefGoogle Scholar
  9. Jordan SA (2004) Large-scale disturbances and their mitigation downstream of shallow cavities covered by a perforated lid. Trans ASME J Fluids Eng 126:851–860CrossRefGoogle Scholar
  10. Kirby R, Cummings A (1998) The impedance of perforated plates subjected to grazing gas flow and backed by porous media. J Sound Vib 217:619–636CrossRefGoogle Scholar
  11. Knotts BD, Selamet A (2003) Suppression of flow-acoustic coupling in sidebranch ducts by interface modification. J Sound Vib 265:1025–1045CrossRefGoogle Scholar
  12. Looijmans NH, Bruggeman JC (1997) Simple vortex models for vibration and noise caused by a flow over louvers in a cavity opening. In: Proceedings of the fluid-structures international aeroelasticity, flow-induced vibration and noise symposium, ASME AD, 53–1, 1:351–359Google Scholar
  13. Ozalp C, Pinarbasi A, Rockwell D (2003) Self-excited oscillations of turbulent inflow along a perforated plate. J Fluids Struct 17:955–970CrossRefGoogle Scholar
  14. Ozalp C, Pinarbasi A, Rockwell D (2005) Self-excited oscillations of flow past a perforated plate: attenuation via three-dimensional surface elements. J Fluids Eng 127:151–164CrossRefGoogle Scholar
  15. Sarno RL, Franke ME (1994) Suppression of flow-induced pressure oscillations in cavities. J Airc 31:90–96CrossRefGoogle Scholar
  16. Sever AC, Rockwell D (2005) Oscillations of shear flow along a slotted plate: small- and large-scale structures. J Fluid Mech 530:213–222zbMATHCrossRefGoogle Scholar
  17. Shaw L (1979) Suppression of aerodynamically induced cavity pressure oscillations. J Acoust Soc Am 66:880–884CrossRefGoogle Scholar
  18. Slomski JF, Zoccola PJ, Ebert MP, Arunajatesan S, Sinha N (2005) Simulation of shear driven cavity flows using unstructured hybrid RANS/LES. 43rd AIAA aerospace sciences meeting and exhibit, Reno, Nevada, January 10–13Google Scholar
  19. Sun X, Jing X, Zhang H, Shi Y (2002) Effect of grazing–bias flow interaction on acoustic impedance of perforated plates. J Sound Vib 254:557–573CrossRefGoogle Scholar
  20. Zoccola PJ (2002) Excitation by flow over an obstructed opening. ASME Appl Mech Div 253:899–906Google Scholar
  21. Zoccola PJ (2004) Effect of opening obstructions on the flow-excited response of a Helmholtz resonator. J Fluids Struct 19:1005–1025CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • E. Celik
    • 1
  • A. C. Sever
    • 1
  • T. Kiwata
    • 1
  • D. Rockwell
    • 1
  1. 1.Department of Mechanical Engineering and Mechanics, 356 Packard LaboratoryLehigh UniversityBethlehemUSA

Personalised recommendations