Effect of Amplitude and Mean Angle of Attack on Wake of an Oscillating Airfoil
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 33085
Effect of Amplitude and Mean Angle of Attack on Wake of an Oscillating Airfoil

Authors: Sadeghi H., Mani M., Ardakani M. A.

Abstract:

The unsteady wake of an EPPLER 361 airfoil in pitching motion has been investigated in a subsonic wind tunnel by hot-wire anemometry. The airfoil was given the pitching motion about the one-quarter chord axis at reduced frequency of 0182. Streamwise mean velocity profiles (wake profiles) were investigated at several vertically aligned points behind the airfoil at one-quarter chord downstream distance from trailing edge. Oscillation amplitude and mean angle of attack were varied to determine the effects on wake profiles. When the maximum dynamic angle of attack was below the static stall angle of attack, weak effects on wake were found by increasing oscillation amplitude and mean angle of attack. But, for higher angles of attack strong unsteady effects were appeared on the wake.

Keywords: Unsteady wake, amplitude, mean angle, EPPLER 361 airfoil.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1332626

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2675

References:


[1] Theodorsen, T., "General Theory of Aerodynamic Instability and the mechanism of Flutter/NACA TR 496, 1935.
[2] Von karman, T., and Sears, W.R., "Airfoil Theory for Non-Uniform Motion", Journal of the Aeronautical Sciences, Vol. 5, No.10, Aug 1983, pp. 379-390.
[3] Lighthill, J., Mathematical Bio-fluid dynamics, SIAM, Philadelphia, 1975.
[4] Wu, T. Y., "Hydromechanics of Swimming of Fishes and Cetaceans", Advances in Applied Mechanics, Vol. 11, 1971, pp.1-63.
[5] McCroskey, W. J., "Some Current Research in Unsteady Fluid Dynamics ÔÇöThe 1976 Free man Scholar Lecture," ASME Transactions, Journal of Fluid Engineering, Vol. 99, March 1977, pp. 8-39.
[6] Carr, L. W., "Progress in Analysis and Prediction of Dynamic Stall," Journal of Aircraft, Vol. 25, Jan 1988, pp.6-17.
[7] E. Tolouei, M. Mani, M. R. Soltani, M. Broomand, "Flow Analysis around a Pitching Airfoil" Paper# AIAA-2004-5200 23rd AIAA Applied Aerodynamics conference 16-19 August 2004 Rhode Island, U.S.A.
[8] M. R .Soltani, M. Mani, E. Tolouei, "An Experimental Investigation of Surface Pressure Variation over an Oscillating Airfoil", The 11th Australian International Aerospace Congress, March 2005, Melbourne Australia.
[9] F. Ajalli, M. Mani, M. Soltani "An Experimental Investigation of Pressure Distribution around a Heaving Airfoil" The 5th International Conference on heat Transfer, Fluid Mechanic and Thermodynamics, 1-4 July 2007, South Africa.
[10] M. Mani, F. Ajalli, M.R. Soltani," An experimental investigation of the reduced frequency effects into pressure coefficients of a plunging airfoil "Seventh International Conference on Advances in Fluid Mechanics, 21, 23 May, 2008.
[11] Satyanarayana, B., "Unsteady Wake Measurements of Airfoil and Cascades," AIAA Journal, Vol. 15, May 1977, pp. 613-618
[12] Koochesfahani, M. M, "Vortical Patterns in the Wake of an Oscillating Airfoil," AIAA Journal, Vol. 27, No. 9, Sep. 1989, pp. 1200-1205.
[13] Park, S.O., Kim, J.S, Lee, B.I., "Hot-Wire Measurements of Near Wakes Behind an Oscillating Airfoil," AIAA Journal Vol. 28, No. 1, 1989.
[14] M. Mani, F. Gudarzi, S.M.H.Karimian," Wake Analysis of a Plunging Airfoil" The 6th International Conference on heat Transfer, Fluid Mechanic and Thermodynamics, 30 June to 2 July 2008, South Africa.