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Transonic buffet on a supercritical aerofoil

Published online by Cambridge University Press:  04 July 2016

B. H. K. Lee*
Affiliation:
National Aeronautical EstablishmentNational Research Council, Canada

Extract

The buffet characteristics of a supercritical aerofoil were investigated in the High Reynolds Number Two-Dimensional Test Facility of the National Aeronautical Establishment (NAE). The test was performed quite deep into the buffet régime. The buffet onset boundary was determined from the divergence of the unsteady balance normal force. Steady and unsteady pressure measurements were obtained for shock-induced separation with reattachment as well as fully separated flows. For flow conditions where discrete shock wave oscillations occurred, ensemble-averaging of the unsteady pressures determined the propagation velocity of the pressure wave induced by periodic shock motion. A model of the self-sustained oscillatory shock motion due to shock-boundary layer interaction was formulated. Broad-band cross-correlations of the pressure field determined the downstream convection velocities of the turbulent eddies of separated flows.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1990 

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References

1. Lee, B.H.K. A method for predicting wing response to buffet loads, J Aircraft, Jan. 1984, 21, (1), pp 8587.Google Scholar
2. Lemley, C.E. and Mullans, R.E. Buffeting pressures on a swept wing in transonic flight - comparison of model and full scale measurements, AIAA Paper No. 73–311, AIAA Dyna mics Specialists’ Conference, Williamsburg, Virginia, March 19–20, 1973.Google Scholar
3. Butler, G.F. and Spavins, G.R. Preliminary evaluation of a technique for predicting buffet loads in flight from wind-tunnel measurements on models of conventional construction, Paper No. 23, AGARD CP–204, Prediction of Aerodynamic Loading, 1976.Google Scholar
4. Mabey, D.G. Prediction of the severity of buffeting, Paper No. 7, AGARD-LS–94, Three-Dimensional and Unsteady Separation at High Reynolds Numbers, 1978.Google Scholar
5. Lee, B.H.K. and Ohman, L.H. Unsteady pressures and forces during transonic buffeting of a supercritical aerofoil, J Aircraft, June 1984, 21, (6), pp 439441.Google Scholar
6. Lee, B.H.K. Investigation of flow separation on a supercritical airfoil, J Aircraft, Nov. 1989, 26, (11), pp 10321037.Google Scholar
7. Lee, B.H.K. Ellis, F.A. and Bureau, J. An investigation of the buffet characteristics of two supercritical airfoils, J Aircraft, Aug. 1989, 26, (8), pp 731736.Google Scholar
8. Lee, B.H.K. Oscillatory shock motion caused by transonic shock-boundary layer interaction, AIAA (to be published).Google Scholar
9. Lee, B.H.K. and Tang, F.C. Transonic buffet of a supercritical airfoil with trailing-edge flap, J Aircraft, May 1989, 26, (5), pp 459464.Google Scholar
10. Rabiner, L.R., Schafer, R.W. and Dlugos, D. Chapter 2.1, Periodgram method for Power Spectrum Analysis, and “Chapter 2.2, Correlation Method for Power Spectrum Estimation”, in: Programs for Digital Signal Processing, Ed. By The Digital Signal Processing Committee, IEEE Acoustics, Speech and Signal Processing Society, IEEE Press, New York, 1979.Google Scholar
11. Ohman, L.H., Plosenski, M.J. and Tang, F.C. Investigation of the Effect of Edgetone Noise on 2-D Test Data for the BGK No. 1 Airfoil, National Research Council of Canada, LTR-HA- 64, June 1982.Google Scholar
12. Ohman, L.H., Brown, D., Chan, Y.Y., Galway, R.D., Hashim, S.M., Kahlid, M., Malek, A., Mokry, M., Tang, N. and Thain, J. New transonic test sections for the NAE 5ft x 5ft trisonic wind tunnel, Paper 34, First Canadian Symposium on Aerodynamics, Ottawa, Canada, December 4–5, 1989.Google Scholar
13. Mundell, A.R.G. and Mabey, D.G. Pressure fluctuations caused by transonic shock/boundary-layer interaction, Aeronaut J, Aug/Sept. 1986, 90, (897), pp 274281.Google Scholar
14. Tijdemen, H. Investigations of the Transonic Flow around Oscillating Airfoils, NLR TR 77090 U, National Aerospace Laboratory, The Netherlands, 1977.Google Scholar
15. Roos, F.W. Some features of the unsteady pressure field in transonic airfoil buffeting, J Aircraft, Nov. 1980, 17, (11), pp 781788.Google Scholar