Skip to main content
Log in

Self-sustained oscillations of turbulent flows over an open cavity

  • Research Article
  • Published:
Experiments in Fluids Aims and scope Submit manuscript

Abstract

The mechanism of self-sustained oscillations in laminar cavity flows has been well characterized; however, the occurrence of self-sustained oscillations in turbulent cavity flows has only previously been characterized by direct observation of flows. Here, the quantitative characteristics of vortical structures in turbulent flows over an open cavity were determined, and then statistical properties were examined for evidence of self-sustained oscillations. Specifically, instantaneous velocity fields were measured using PIV and wall pressure fluctuations were determined from microphone data. Cavity geometries of L/= 1 and 2, where L and D are the length and depth of the cavity, respectively, were used under conditions where the incoming boundary layer was turbulent at Re θ  = 830. Statistical analyses were applied based on the instantaneous velocity fields of PIV data. The spatial distributions of vertical velocity correlations (v–v) showed alternating patterns that reflect the organized nature of the large-scale vortical structures corresponding to the modes of = 2 for L/= 1 and = 3 for L/= 2. These values were consistent with the numbers of vortical structures obtained from a modified version of Rossiter’s equation. Furthermore the numbers of vortical structures determined in the statistical analyses were consistently observed in instantaneous distributions of the swirling strength (λ ci). The incoming turbulent boundary layer can give rise to the formation of large-scale vortical structures responsible for self-sustained oscillations.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15

Similar content being viewed by others

Abbreviations

D :

depth of the cavity (mm)

δ :

boundary layer thickness (mm)

δ ω :

vorticity thickness (mm)

Δ:

filter width

f :

filter function

L :

length of the cavity (mm)

L eff :

effective length scale (mm)

ΔL l :

length of contamination near the leading edge

ΔL t :

length of contamination near the trailing edge

λ ci :

swirling strength

λ x :

streamwise wavelength of vortical structure (mm)

θ :

momentum thickness (mm)

R vv :

v–v two point correlation coefficient

R θ :

Reynolds number based on the momentum thickness

R D :

Reynolds number based on the depth of the cavity

St L :

Strouhal number based on the length of the cavity

\( \ifmmode\expandafter\bar\else\expandafter\=\fi{u} \) :

filtered instantaneous velocity (m/s)

U c,avg :

convection velocity (m/s)

v rms :

root mean square of vertical velocity (m/s)

x 0 :

streamwise position of reference point (mm)

y 0 :

vertical position of reference point (mm)

References

  • Ahuja K, Mendosa J (1995) Effects of cavity dimensions, boundary layer and temperature on cavity noise with emphasis on benchmark data to validate computational aeroacoustics codes. Final Report Contract NASA-19061, Task 13. NASA Contract Report

  • Adrian RJ, Christensen T, Liu Z (2000) Analysis and interpretation of instantaneous turbulent velocity fields. Exp Fluids 29:275–290

    Article  Google Scholar 

  • Ashcroft C, Zhang X (2005) Vortical structures over rectangular cavities at low speed. Phys Fluids 17:015104

    Article  Google Scholar 

  • Brown G, Roshko A (1974) On density effects and large structure in turbulent mixing layers. J Fluid Mech 64:775–816

    Google Scholar 

  • Burroughs CB, Stinebring DR (1994) Cavity flow tones in water. J Acoust Soc Am 95(3):1256–1263

    Article  Google Scholar 

  • Chang KC, Constantinescu G, Park SO (2006) Analysis of the flow and mass transfer processes for the incompressible flow past an open cavity with a laminar and a fully turbulent incoming boundary layer. J Fluid Mech 561:113–145

    Article  MATH  Google Scholar 

  • Chatellier L, Laumonier Y, Gervais Y (2004) Theoretical and experimental investigations of low Mach number turbulent cavity flows. Exp Fluids 36:728–740

    Article  Google Scholar 

  • Gharib M, Roshko A (1987) The effect of flow oscillations on cavity drag. J Fluid Mech 177:501–530

    Article  Google Scholar 

  • Grace SM, Dewar WG, Wroblewski DE (2004) Experimental investigation of the flow characteristics within a shallow wall cavity for both laminar and turbulent upstream boundary layers. Exp Fluids 36:791–804

    Article  Google Scholar 

  • Hart DP (2000) PIV error correction. Exp Fluids 29:13–22

    Article  Google Scholar 

  • Howe MS (1997) Low Strouhal number instabilities of flow over apertures and wall cavities. J Acoust Soc Am 102(2):772–780

    Article  Google Scholar 

  • Larchevêque L, Sagaut P, Mary I, Labbé O (2003) Large-eddy simulation of a compressible flow past a deep cavity. Phys Fluids 15:193–210

    Article  Google Scholar 

  • Lee SB, Sung HJ (2007) Influence of upstream turbulence on self-sustained oscillations in an open cavity. J Turbulence (submitted)

  • Lin JC, Rockwell D (2001) Organized oscillations of initially turbulent flow past a cavity. AIAA J 39(6):1139–1151

    Article  Google Scholar 

  • Little J, Debiasi M, Caraballo E, Samimy M (2007) Effects of open-loop and closed-loop on subsonic cavity flows. Phys Fluids 19(6):065104-065104-15

    Google Scholar 

  • Liu YZ, Kang W, Sung HJ (2005) Assessment of the organization of a turbulent separated and reattaching flow by measuring wall pressure fluctuations. Exp Fluids 38:485–493

    Article  Google Scholar 

  • Rockwell D, Kinsely C (1980) Observation of the three-dimensional nature of unstable flow past a cavity. Phys Fluids 23:425–431

    Article  Google Scholar 

  • Rockwell D, Naudascher E (1978) Review-self-sustaining oscillations of flow past cavities. J Fluids Eng 100:152–165

    Google Scholar 

  • Rockwell D, Naudascher E (1979) Self-sustained oscillations of impinging free shear layer. Annu Rev Fluid Mech 11:67–94

    Article  Google Scholar 

  • Rossiter JE (1964) Wind-tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds. Aeronautical Research Council Reports and Memoranda No. 3438

  • Sarohia V (1977) Experimental investigation of oscillations in flows over shallow cavities. AIAA J 15(7):984–999

    Article  Google Scholar 

  • Ukeiley L, Murray N (2005) Velocity and surface measurements in an open cavity. Exp Fluids 38:656–671

    Article  Google Scholar 

  • Yao H, Cooper RK, Raghunathan S (2004) Numerical simulation of incompressible laminar flow over three-dimensional rectangular cavities. J Fluids Eng 126:919–927

    Article  Google Scholar 

  • Zhou J, Adrian RJ, Balachandar S, Kendall TM (1999) Mechanism for generating coherent packets of hairpin vortices in channel flow. J Fluid Mech 387:353–396

    Article  MATH  MathSciNet  Google Scholar 

Download references

Acknowledgments

This work was supported by the Creative Research Initiatives of the Korea Science and Engineering Foundation.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hyung Jin Sung.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kang, W., Lee, S.B. & Sung, H.J. Self-sustained oscillations of turbulent flows over an open cavity. Exp Fluids 45, 693–702 (2008). https://doi.org/10.1007/s00348-008-0510-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00348-008-0510-8

Keywords

Navigation