Experimental Study on the Effect of Skin Flexibility on Aerodynamic Performance of Flapping Wings for Micro Air Vehicles


Article Preview

In the present study, the aerodynamic characteristics such as time-averaged lift and drag generation of two flexible membrane (latex thin and thick) wings with different skin flexibilities are compared with those of a conventional rigid (wood) wing to assess the effects of skin flexibility (rigidity) on the aerodynamic performance for flapping flight applications. The experiments are performed in an open circuit wind tunnel of non-return airflow with a test section of (0.3m x 0.3m) and is capable of speeds from 0.5 to 30 m/s. The time-averaged lift and drag as functions of flapping frequency, forward flight velocity and the orientation angle of the flapping motions with respect to the incoming flows are measured by using a strain gauge balance and KYOWA PCD-300A sensor interface data acquisition system. It has been found that flapping motion would bring significant aerodynamic benefits when the flapping flight is in unsteady state regime, with advance ratio less than 1.0. The aerodynamic benefits are found to decay exponentially with the increasing advance ratio. Flapping motion is found to become detrimental for high speed flight applications. It is also observed that the skin flexibility has considerable effect on the aerodynamic performance. The flexible latex thick wing is found to have better overall aerodynamic performance over the rigid wing, especially for low speed applications. The wood (rigid) wing exhibited better lift production performance in quasi steady regime.



Edited by:

R. Varatharajoo, F.I. Romli, K.A. Ahmad, D.L. Majid and F. Mustapha




H. Yusoff et al., "Experimental Study on the Effect of Skin Flexibility on Aerodynamic Performance of Flapping Wings for Micro Air Vehicles", Applied Mechanics and Materials, Vol. 629, pp. 18-23, 2014

Online since:

October 2014




* - Corresponding Author

[1] Norberg, U.M. 1976. Aerodynamics, kinematics, and energetics of horizontal flapping flight in the long-eared bat plecotusauritus. J. exp. Biol. (1976), 65, 179-212.

[2] Shyy, W., Berg, M., Ljungqvist, D. 1999. Flapping and flexible wings for biological and micro air vehicles, Progress in Aerospace Sciences 35 (1999) 455-505.

DOI: https://doi.org/10.1016/s0376-0421(98)00016-5

[3] Galvao, R., Emily, I., Song, A., Tian, X., Bishop, K., Swartz, S., Breuer, K. 2006. The aerodynamics of compliant membrane wings modeled on mammalian flight mechanics. Paper No. AIAA 2006-2866, 36th AIAA Fluid Dynamics Conference and Exhibit. 5 - 8 June 2006, San Francisco, California.

DOI: https://doi.org/10.2514/6.2006-2866

[4] Song, A., Tian, X., Israeli, E., Galvao, R., Bishop, K., Swartz, S., Breue K. 2008. Aeromechanics of membrane wings with implications for animal flight. AIAA Journal 2008; 46(8): 2096-2106.

DOI: https://doi.org/10.2514/1.36694

[5] Ho, S., Nassef, H., Pornsinsirirak, N., Tai, Y. -C. Chih-Ming Hoa. Unsteady aerodynamics and flow control for flapping wing flyers, Progress in Aerospace Sciences 39 (2003) 635–681.

DOI: https://doi.org/10.1016/j.paerosci.2003.04.001

[6] Zhao, L., Huang, Q., Deng, X., Sane, S.P. Aerodynamic Effects of Flexibility in Flapping Wings. Journal of the Royal Society Interface (2010) 7: 485–497.

DOI: https://doi.org/10.1098/rsif.2009.0200

[7] Mazaheri, K., Ebrahimi, A. Experimental investigation of the effect of chordwise flexibility on the aerodynamics of flapping wings in hovering flight. Journal of Fluids and Structures (2010) 26: 544–558.

DOI: https://doi.org/10.1016/j.jfluidstructs.2010.03.004

[8] Yusoff, H., Abdullah, MZ., Mujeebu, MA., Ahmad, KA., Development of Flexible Wings and Flapping Mechanism with Integrated Electronic Control System for Micro Air Vehicle Research. Experimental Techniques (2013) 37: (4), 25-37.

DOI: https://doi.org/10.1111/j.1747-1567.2011.00729.x

[9] Yusoff, H., Abdullah, MZ., Mujeebu, MA., Ahmad, KA., Effect of Skin Flexibility on Aerodynamic Performance of Flexible Skin Flapping Wings for Micro Air Vehicles. Experimental Techniques (2012) DOI: 10. 1111/ext. 12004, 1-10.

DOI: https://doi.org/10.1111/ext.12004