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Effect of amplitude and mean angle-of-attack on the boundary layer of an oscillating aerofoil

Published online by Cambridge University Press:  03 February 2016

M. R. Soltani  and
A. Bakhshalipour
M. R. Soltani
Affiliation:
Sharif University of Technology, Department of Aerospace Engineering, Tehran, Iran
A. Bakhshalipour
Affiliation:
Sharif University of Technology, Department of Aerospace Engineering, Tehran, Iran
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Abstract

Extensive experiments were conducted to study the effect of various parameters on the surface pressure distribution and transition point of an aerofoil section used in a wind turbine blade. In this paper details of the variation of transition point on the aforementioned aerofoil are presented. The aerofoil spanned the wind-tunnel test section and was oscillated sinusoidally in pitch about the quarter chord. The imposed variables of the experiments were free stream velocity, amplitude of motion, mean angle-of-attack, and oscillation frequency.

The spatial-temporal progressions of the leading-edge transition point and the state of the unsteady boundary-layer were measured using eight closely-spaced, hot-film sensors (HFS). The measurements show that:

(i) Reduced frequency has a pronounced effect on the variations of the transition point.

(ii) There exists a hysteresis loop in the dynamic transition location and its shape varies with the reduced frequency and mean angle-of-attack.

Type
Research Article
Information
The Aeronautical Journal , Volume 112 , Issue 1138 , December 2008 , pp. 705 - 713
Copyright
Copyright © Royal Aeronautical Society 2008 

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References

1. Maresca, C., Favier, D. and Rebont, J., Experiments on an aerofoil at high angle of incidence in longitudinal oscillations, J Fluid Mechanics, 1979, 92, pp 671–690.Google Scholar
2. Broeren, A.P. and Bragg, M.B., Spanwise variation in the unsteady stalling flowfields of two-dimensional aerofoil models, AIAA J, September 2001, 39, (9), pp 1641–1651.Google Scholar
3. Walker, J.M., Helin, H.E. and Chow, D.C., Unsteady surface pressure measurement on a pitching aerofoil, AIAA-85-0532, AIAA Shear Flow Control Conference, 12-14 March 1985.Google Scholar
4. Leishman, J.G., Challenges in modeling the unsteady aerodynamics of wind turbines, AIAA 2002-0037, 21 ASME Wind Energy Symposium and the 40 AIAA Aerospace Sciences Meeting, 14-17 January 2002.Google Scholar
5. Huyer, S.A., Simms, D.A. and Robinson, M.C., Unsteady aerodynamics associated with a horizontal-axis wind turbine, AIAA J, 1996, 34, (7), pp 1410–1419.Google Scholar
6. Soltani, M.R., Bakhshalipour, A. and Seddigh, M., Effect of amplitude and mean angle-of-attack on the unsteady surface pressure of a pitching aerofoil, J Aerospace Science and Technology, 2005, 2, (4), pp 27–36.Google Scholar
7. Bertoloti, F.P., Transition Modeling Based on the PSE, Lecture Notes from the ERCOFTAC/IUTAM, Summer-School, Stockholm, Sweden, Kluwer Academic Publishers, 1995, pp 337–368.Google Scholar
8. Dan Sommers, M. and Tangler, J.L., Wind-tunnel tests of two aerofoils for wind turbines operating at high Reynolds numbers, Presented at the ASME Wind Energy Symposium, Reno, Nevada, USA, January 2000.Google Scholar
9. Soltani, M.R., Askary, F. and Bakhshalipour, A., Effect of surface roughness on the aerodynamic performance of a section of a wind turbine blade, J Science and Technology, Sharif University of Technology, 2007, (37), pp 49–58.Google Scholar
10. Eppler, R. and Somers, D.M., A computer program for the design and analysis of low-speed aerofoils, NASA TM 80210, 1980.Google Scholar
11. Drela, M. and Giles, M.B., A computer program for the design and analysis of low-speed aerofoils, 1986.Google Scholar
12. Soltani, M.R. and Bakhshalipour, A., Measurement of transition point on a section of a wind turbine blade using hot film sensors, 6th conference of the Iranian Aerospace Society, 24-25 February 2007.Google Scholar
13. Carr, L.W., McCroskey, W.J., McAlister, K.W., Pucci, S.L. and Lambert, O., An experimental study of dynamic stall on advanced aerofoil sections, 3, Hot-Wire and Hot-Film Measurements, NASA TM-84245, December 1982.Google Scholar
14. Ericsson, L.E., A critical look at dynamic simulation of viscous flow, paper No. 6, AGARD-CP-38, May 1985 Google Scholar