Shu-Wei Chuang1, Fuh-Lin Lih2 and Jr-Ming Miao This email address is being protected from spambots. You need JavaScript enabled to view it.3

1Institute of Weapon Systems, Chung Cheng Institute of Technology, National Defense University, Taoyuan, Taiwan 335, R.O.C.
2Center of General Education, R.O.C. Military Academy, Kaohsiung, Taiwan 830, R.O.C.
3Department of Biomechatronic Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan 912, R.O.C.


 

Received: April 23, 2012
Accepted: May 30, 2012
Publication Date: September 1, 2012

Download Citation: ||https://doi.org/10.6180/jase.2012.15.3.05  


ABSTRACT


The effects of the Reynolds number and inclined angle of stroke plane on the generating lift and thrust forces of a flapping corrugated airfoil was studied by numerical simulations with dynamic deformable meshes. The chord Reynolds number (Re) based on the incoming airstream velocity is varied from 103 to 104 with interval of 103 . Two different inclined angles of stroke plane on the aerodynamic forces of corrugated airfoil were also considered. Due to the corrugated shape of dragonfly wings varied depending on the cross section location chosen, present tested profile of airfoil was selected from the mid-span of wing of an Aeshna cyanea dragonfly forewing. Unsteady flows over a corrugated thin airfoil and a flat-plate executing flapping motion are computed with time-dependent two-dimensional laminar incompressible Navier-Stokes equations. The dynamic mesh technique is applied to model the flow field of cyclical flapping motion of a corrugated airfoil under different combinations of pitch angle and stroke amplitude. Instant vorticity contours over a complete flapping cycle of a corrugated airfoil and a flat-plate clearly reveals the flow mechanisms for lift force generation are dynamic stall, rotational circulation, and wake capture. The thrust force is dominated by the formation of leading edge vortex (LEV) and trailing edge vortex (TEV) shedding downstream to form a reverse von Karman vortex. Results indicated that there is little difference on the aerodynamic force between corrugated airfoil and flat-plate under tested range of flapping frequency. The mean lift force coefficient of corrugated airfoil was enhanced with the increasing of Re. Visible changes in the mean lift force coefficient can be identified from the variation of inclined angle of stroke plane at a fixed Re. The critical products of reduced frequency and stroke amplitude to generate the positive mean thrust force output of a corrugated airfoil was given in present work.


Keywords: Bio-inspired MAV, Corrugated airfoil, CFD, Reynolds number, Inclined angle of stroke plane


REFERENCES


  1. [1] Dudley, R., The Biomechanics of Insect Flight: Form, Function, Evolution, Princeton University Press, Princeton, NJ, USA (2000).
  2. [2] Anderson, J. M., Streitlien, K., Barrett, D. S. and Triantafyllou, M. S., “Oscillating Foils of High Propulsive Efficiency,” Journal of Fluid Mechanics, Vol. 360, pp. 4172 (1988).
  3. [3] Ansari, A. A., Phillips, N., Stabler, G., Wilkins, P. C., Zbikowski, R. and Knowles, K., “Experimental Investigation of Some Aspects of Insect-Like Flapping Flight Aerodynamics for Application to Micro Air Vehicles,” Exp. Fluids, Vol. 46, pp. 777798 (2009).
  4. [4] Chandar, D. and Damodaran, M., “Computational Study of Unsteady Low Reynolds Number Airfoil Aerodynamics on Moving Overlapping Meshes,” AIAA Journal, Vol. 46, pp. 429438 (2008).
  5. [5] Dickinson, M. H., Lehmann, F. O. and Sane, S. P., “Wing Rotation and the Aerodynamic Basis of Insect Flight,” Science, Vol. 284, pp. 19541960 (1999).
  6. [6] Isaac, K. M., Rolwes, J. and Colozza, A., “Aerodynamics of a Flapping and Pitching Wing Using Simulations and Experiments,” AIAA Journal, Vol. 46, pp. 15051515 (2008).
  7. [7] Miao, J. M., Sun, W. S. and Tai, C. H., “Numerical Analysis on Aerodynamic Force Generation of Biplane Counter-Flapping Flexible Airfoils,” Journal of Aircraft, Vol. 46, pp. 17851794 (2009).
  8. [8] Rees, C. J. C., “Form and Function in Corrugated Insect Wings,” Nature, Vol. 256, pp. 200203 (1975).
  9. [9] Sudo, S. and Tsuyuki, K., “Wing Morphology of Some Insects,” JSME Int. C., Vol. 43, pp. 895900 (2000).
  10. [10] Vargas, A., Mittal R. and Dong H., “A Computational Study of the Aerodynamic Performance of a Dragonfly Wing Section in Gliding Flight,” Bioinspiration & Biomimetics, Vol. 3, pp. 113 (2008).
  11. [11] Kim, W. P., Ko, J. H., Park, H. C. and Byun, D., “Effects of Corrugation of the Dragonfly Wing on Gliding Performance,” J. Theor. Biol., Vol. 260, pp. 523530 (2009).
  12. [12] Du, G. and Sun, M., “Effects of Wing Deformation on Aerodynamic Forces in Hovering Hoverflies,” J. Exp. Biol., Vol. 213, pp. 22732283 (2010).
  13. [13] Meng, X. G., Xu, L. and Sun, M., “Aerodynamic Effects of Corrugation in Flapping Insect Wings in Hovering Flight,” J. Exp. Biol., Vol. 214, pp. 432444 (2011).
  14. [14] Meng, X. G. and Sun, M., “Aerodynamic Effects of Corrugation in Flapping Insect Wings in Forward Flight,” J. Bionic Engineering, Vol. 8, pp. 140150 (2011).
  15. [15] Sun, W. H., Miao, J. M., Tai, C. H. and Hung, C. C., “Optimization Approach on Flapping Characteristics of Corrugated Airfoil,” World Academy of Science, Engineering and Technology, Vol. 74, pp. 370377 (2011).