Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-27T23:02:53.707Z Has data issue: false hasContentIssue false
  • English
  • Français

Computational study of flowfield characteristics in cavities with stores

Published online by Cambridge University Press:  27 January 2016

B. Khanal ,
K. Knowles  and
A. J. Saddington
B. Khanal*
Affiliation:
Dept. of Engineering Science, University of Oxford, Oxford, UK
*
[email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

In this paper, the results of computational studies on the unsteady flow features in three-dimensional empty cavities and cavities with a representative store are presented. Flow simulations with a turbulence model based on a hybrid method, which behaves as a standard Reynolds-averaged Navier-Stokes (RANS) model within the attached boundary layer and as a Large-Eddy Simulation LES sub-grid scale model in the rest of the flow (commonly known as Detached-Eddy Simulation (DES)) are used in this study. The time-mean flow study showed the presence of three-dimensional effects inside the cavities. The mean flowfield visualisation also clearly showed the presence of a pair of ‘tornado-like’ vortices in the upstream half of the cavity which merge to a single, large recirculation further downstream. Visualisation for the cavity-with-store case revealed that the mean flowfield was effectively divided into two halves with significant reduction of the spanwise flow across the cavity width. In the unsteady flow study, near-field acoustic spectra were computed for the empty cavity and cavity-with-store cases. Study of unsteady pressure spectra for the cavity-with-store case found the presence of many peaks and the corresponding mode frequencies were found to agree well with the Rossiter modes. The blockage effect of store and strut on the spanwise flow is thought to have reduced the interaction, and subsequent non-linear coupling, between the Rossiter modes. This may be the reason for the co-existence of multiple modes without the coupling among them.

Type
Research Article
Information
The Aeronautical Journal , Volume 115 , Issue 1173 , November 2011 , pp. 669 - 681
Copyright
Copyright © Royal Aeronautical Society 2011 

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

1. Dix, R.E. and Bauer, R.C. Experimental and predicted acoustic amplitudes in a rectangular cavity, No. AIAA–2002–0472, 2000.Google Scholar
2. Srinivisan, S. and Baysal, O. Navier-Stokes calculations of transonic flow past cavities, J Fluid Engineering, September 1991, 113, pp 369–376.Google Scholar
3. Tam, C.K.W. and Block, P.J.W. On the tones and pressure oscillations induced by flow over rectangular cavities, J Fluid Mechanics, 1978, 89, pp 373–399.Google Scholar
4. Stallings, R. and Wilcox, F. Experimental cavity pressure distributions at supersonic speeds, Tech Rep NASA–TP–2683, NASA, June 1987.Google Scholar
5. Xiao, X., Edwards, J.R. and Hassan, H.A. Blending functions in hybrid large-eddy/Reynolds-averaged Navier-Stokes simulations, AIAA J, 2004, 42, (12), pp 2508–2515.Google Scholar
6. Spalart, P.R. and Allmaras, S.R. Comments on the feasibility of LES for wings and on a hybrid RANS/LES approach, Proceedings of first AFOSR international conference on DNS/LES, Ruston, Louisiana, USA, August 1997.Google Scholar
7. Nichols, R.H. Comparison of hybrid turbulence models for a circular cylinder and a cavity, AIAA J, 2006, 46, (6), pp 1207–1219.Google Scholar
8. Sinha, N., Dash, S., Chidambaram, N. and Findlay, D. A Perspective on the Simulation of Cavity Aeroacoustics, No. AIAA–1998–0286, January 1998.Google Scholar
9. Spalart, P.R., Deck, S., Shur, M.L., Squires, K.D., Strelets, M.K. and Travin, A. A new version of detached-eddy simulation, resistant to ambiguous grid densities, Theoritical and Computational Fluid Dynamics, 2006, 20, pp 181–195.Google Scholar
10. Charwat, A.F., Roos, J.N., Dewey, F.C. and Hitz, J.A. An investigation of separated flows Part 1: The pressure field, J Aerospace Sciences, 1961, 28, (6), pp 457–470.Google Scholar
11. Charwat, A.F., Roos, J.N., Dewey, F.C. and Hitz, J.A. An investigation of separated flows Part 2 : Flow in the cavity and heat transfer, J Aerospace Sciences, 1961, 28, (7), pp 513–527.Google Scholar
12. ESDU, Aerodynamics and aero-acoustics of rectangular planform cavities. Part I: Timeaveraged flow, IHS ESDU, London, UK, 2004, ESDU Data Item 02008.Google Scholar
13. Plentovich, E. Three-dimensional cavity flow fields at subsonic and transonic speeds, Tech Rep NASA–TM–4209, NASA Langley Research Center, USA, 1992.Google Scholar
14. Tracy, M.B. and Plentovich, E. Measurements of fluctuating pressure in a rectangular cavity in transonic flow at high Reynolds number, Tech Rep NASA–TM–4363, NASA Langley Research Center, 1992.Google Scholar
15. Rossiter, J. Wind-tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds, Tech Rep 3438, Aeronautical Research Council Reports and Memoranda, 1966.Google Scholar
16. Heller, H., Holmes, D. and Covert, E. Flow-induced pressure oscillations in shallow cavities, J Sound and Vibration, 1971, 18, pp 545–553.Google Scholar
17. Khanal, B., Knowles, K. and Saddington, A. Computational Study of Cavity Flowfield at Transonic Speeds, No. AIAA–2009–701, 47th AIAA Aerospace Sciences Meeting, Orlando, Florida, USA, 2009.Google Scholar
18. Kim, S., Dai, Y., Koutsavdis, E.K., Sovani, S., Kadam, N.A. and Ravuri, K.M.R. A Versatile Implementation of Acoustic Analogy Based Noise Prediction Method in a General-Purpose CFD Code, No. AIAA–2003–3202, 9th AIAA/CEAS Aeroacoustics Conference and Exhibit, Hilton Head, South Carolina, USA, May 2003.Google Scholar
19. Mathey, F., Morin, O., Caruelle, B. and Debatin, K. Simulation of aeroacoustic sources in aircraft climate control systems, No. AIAA–2006–2493, 12th AIAA/CEAS Aeroacoustics Conference and Exhibit, Cambridge, Massachusetts, USA, May 2006.Google Scholar
20. Spalart, P.R. and Allmaras, S.R. A one-equation turbulence model for aerodynamic flows, No. AIAA–1992–0439, 30th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada, USA, January 1992.Google Scholar
21. Stallings, R.L., Plentovich, E.B., Tracey, M.B. and Hemsch, M.J., Measurements of store forces and moments and cavity pressures for a generic store in and near a box cavity at subsonic and transonic speeds, Tech Rep NASA–TM–4611, NASA, May 2002.Google Scholar
22. Knowles, R.D., Finnis, M.V., Saddington, A.J. and Knowles, K. Planar visualization of vortical flows, Proceedings of IMechE Part G: J Aerospace Engineering, 2006, 220, (G6), pp 619–627, Special Issue on Integrating CFD and Experiments in Aerodynamics.Google Scholar
23. Atvars, K., Knowles, K., Ritchie, S.A. and Lawson, N.J. Experimental and computational investigation of an ‘open’ transonic cavity flow, Proceedings of the Institution of Mechanical Engineers, Part G: J Aerospace Engineering, 2009, 23, (4), pp 357–368.Google Scholar
24. Khanal, B., Knowles, K. and Saddington, A.J. Study of cavity unsteady flowfield, No. ISSN0377-8312, 4th Symposium on Integrating CFD and Experiments in Aerodynamics, Belgium, 2009.Google Scholar
25. Taborda, N.M., Bray, D. and Knowles, K. Visualisation of three-dimensional cavity flows, No. ExHFT5, In 5th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Thessaloniki, Greece, 2001.Google Scholar