Numerical Analysis of the Unsteady Subsonic Flow around a Plunging Airfoil

Title & Authors
Numerical Analysis of the Unsteady Subsonic Flow around a Plunging Airfoil
Lee, Kyungwhan; Kim, Jaesoo;

Abstract
Much numerical and experimental research has been done for the flow around an oscillating airfoil. The main research topics are vortex shedding, dynamic stall phenomenon, MAV's lift and thrust generation. Until now, researches mainly have been concentrated on analyzing the wake flow for the variation of frequency and amplitude at a low angle of attack. In this study, wake structures and acoustic wave propagation characteristics were studied for a plunging airfoil at high angle of attack. The governing equations are the Navier-Stokes equation with LES turbulence model. OHOC (Optimized High-Order Compact) scheme and 4th order Runge-Kutta method were used. The Mach number is 0.3, the Reynolds number is, and the angle of attack is from $\small{20^{\circ}}$ to $\small{50^{\circ}}$. The plunging frequency and the amplitude are from 0.05 to 0.15, and from 0.1 to 0.2, respectively. Due to the high resolution numerical method, wake vortex shedding and pressure wave propagation process, as well as the propagation characteristics of acoustic waves can be simulated. The results of frequency analysis show that the flow has the mixed characteristics of the forced plunging frequency and the vortex shedding frequency at high angle of attack.
Keywords
Plunging Airfoil;OHOC(Optimized High Order Compact ) Scheme;Frequency Analysis;Subsonic Unsteady Flow;
Language
English
Cited by
References
1.
Platzer, M.F., Jones, K.D., and Young J., "Flapping Wing Aerodynamics: Progress and Challemges", AIAA Journal, Vol. 46, No. 9, 2008, pp. 2136-2149.

2.
Isogai, K., Shinmoto, Y., and Watanabe Y., "Effects of Dynamic Stall on Propulsive Efficiency and Thrust of Flapping Airfoil", AIAA Journal, Vol. 37, No. 10, 1999, pp. 1145-1151.

3.
Birnbaum, W., "Das ebene Problem des Schlagenden Fluegels", Zeitschrift fuer Angewandte Mathematik und Mechanical, Vol. 4, No. 4, 1924, pp. 277-292.

4.
Garrick, I.E., "Propulsion of a Flapping and Oscillating Airfoils", NACA Rept. 567, 1936.

5.
Jones, K.D., Dohring, C.M., and Platzer, M.F., "Experimental and Computational Investigation of the Knoller-Benz Effect", AIAA Journal, Vol. 36, No. 7, 1998, pp. 1240-1246.

6.
Lai, J.C.S., and Platzer, M.F., "Jet Characteristics of a Plunging Airfoil", AIAA Journal, Vol. 37, No. 12, 1999, pp. 1529-1537.

7.
Taylor, G.K., Nudds, R.L., and Thomas, A.L.R., "Flying and Swimming Animals Cruise at a Strouhal Number Tuned for High Power Efficiency", Nature (London), Vol. 425, Oct., 2003, pp. 707-711.

8.
Young, J., and Lai, J.C.S., "Oscillation Frequency and Amplitude Effects on the Wake of a Plunging Airfoil", AIAA Journal, Vol.42, No.10, 2004, pp. 2042-2052.

9.
Rival, D., and Tropea, C., "Characteristics of Pitching and Plunging Airfoils under Dynamic-Stall Conditions", Journal of Aircraft, Vol. 47, No. 1, 2010, pp. 80-86.

10.
Moryossef, Y., and Levy, Y., "Effect of Oscillations on Airfoils in Close Proximity to the Ground", AIAA Journal, Vol. 42, No. 9, 2004, pp. 1755-1764.

11.
Wagner, C., Huttl, T., and Sagaut, P., Large-Eddy Simulation for Acoustics, CAMBRIDGE UNIVERSITY PRESS, 2007.

12.
Wilcox, D.C., Turbulence Modeling for CFD, 2nd., DCW Industries Inc., California, 2000.

13.
Kim, J.W., and Lee, D.J., "Optimizes Compact Finite Difference Schemes with maximum Resolution", AIAA Journal, Vol. 34, No. 5, 1986, pp. 887-893.

14.
Sandberg, R.D., Jones, L.E., and Sandham, N.D., "A Zonal Characteristic Boundary Condition for Numerical Simulations of Aerodynamic Sound", ECCOMA CFD, 2006.

15.
Kim, T.S., and Kim, J.S., "Numerical Analysis of the Three Dimensional Wake Flow and Acoustic Field around a Circular Cylinder", Int. J. of Aeronautical and Space Sciences, Vol. 11, No. 4, 2010, pp. 319-235.

16.
Blake, W.K., "Dipole Sound from Cylinders", Mechanics of Flow induced Sound and Vibration, Vol. 1, Academic Press, New York, 1986, pp. 219-287.

17.
Williamson, C.H.K., "Three Dimensional Wake Transition", Journal of Fluid Mechanics, Vol. 328, 1996, pp. 345-407.

18.
Yoo, J.K., and Kim, J.S., "Analysis of Unsteady Oscillating Flow around Two Dimensional Airfoil at High Angle of Attack", J. Comput. Fluids Eng., Vol. 18, No. 1, 2013, pp. 1-6.

19.
Liu, Y., Li, K., Zhang, J., Wang, H., and Liu, L., "Numerical Bifurcation Analysis of Static Stall of Airfoil and Dynamic Stall under Unsteady Perturbation", Commun Nonlinear Sci Numer Simulat, Vol. 17, No. 8, 2012, pp. 3427-3434.

20.
Critzos, C.C., Heyson, H.H., and Boswinkle, R.W.," Aerodynamic Characteristics of NACA0012 Airfoil Section at the Angle of Attack from \$0^{\circ}\$to \$180^{\circ}\$", NACA TN 3361, 1955.

21.
Craig, A.P., and Hansman, R.J., "An Experimental Low Reynolds Number Comparison of a Wortmann FX67-K170 Airfoil, a NACA0012 Airfoil, and a NACA 64-210 Airfoil in Simulated Heavy Rain", NACA CR 181119, 1987.

22.
Hoerner, S.F., and Borst, H.V., Fluid Dynamic Lift, Horerner Fluid Dynamics, U.S.A., 1985, pp. 2-17 - 4-26.