Wake Frequency Analysis of a Plunging Airfoil with Trailing-Edge Strips


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Experimental measurements were conducted on a plunging Eppler 361 strip flapped airfoil to study wake structure in the wake. The heights of strip flap were 2.6% and 3.3% chord. The velocity in the wake was measured by hot-wire anemometry. It was found that the trailing-edge strip had different effects on the plunging wake profile during the oscillation cycle. At initial angle of 0 degree, the trailing-edge strip causes more velocity defect in the oscillation phases of 180º and 270º. At high initial angle 12 degrees, a significant decrease in value of velocity is found at 180º because of the leading edge vortex shedding. The power spectra of dominant frequencies were significantly increased by fitting the strip flap on the plunging airfoil.



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Edited by:

R. Varatharajoo, E. J. Abdullah, D. L. Majid, F. I. Romli, A. S. Mohd Rafie and K. A. Ahmad




F. Ajalli et al., "Wake Frequency Analysis of a Plunging Airfoil with Trailing-Edge Strips", Applied Mechanics and Materials, Vol. 225, pp. 3-7, 2012

Online since:

November 2012




[1] R.H. Liebeck , Design of Subsonic Airfoils for High Lift, J. Aircr. 15 (1978) 547–561.

DOI: https://doi.org/10.2514/3.58406

[2] R. Myose, M. Papadakis, I. Heron, Gurney flap experiments on airfoils, wings, and reflection plane model, J. Aircr. 35 (1998) 206–211.

DOI: https://doi.org/10.2514/2.2309

[3] D.H. Neuhart, O.C. Pendergraft, A water tunnel study of Gurney flaps, NASA TM 4071 (1998).

[4] Y. Li, J. Wang, P. Zhang, Effects of Gurney flaps on a NACA 0012 airfoil, Flow Turb. and Comb. 68 (2002) 27–39.

[5] T.S. Liu, J. Montefort, Thin airfoil theoretical interpretation for Gurney flap lift enhancement, J. Aircr. 44 (2007) 667–671.

DOI: https://doi.org/10.2514/1.27680

[6] P. Gerontakos, T. Lee, Oscillating wing loadings with trailingedge strips, J. Aircr. 43 (2006) 428–436.

[7] P. Gerontakos, T. Lee, Particle image velocimetry investigation of flow over unsteady airfoil with trailing-edge strip, Exp. Fluids 44 (2008) 539-556.

DOI: https://doi.org/10.1007/s00348-007-0414-z