Wind Tunnel Test for Drag Reduction of Airfoil Bionic Soft Surface

Abstract:

The soft surface of birds and aquatic organisms in the nature can effectively reduce the drag. Inspired by the fact,in this paper, an attempt is made to stick silicone rubber soft surface on the surfaces of NACA 4412 and NACA 6409 airfoils. The drags, lifts and lift-drag ratios of airfoils with soft and rigid surfaces in 5 different thickness were compared through wind tunnel test under the condition of α = 0 °. The results show that most of the bionic soft surfaces play the role of reducing the aerodynamic drag, and also increasing the lift at the same time, in which the soft surface of 0.6mm had the most significant effect of drag reduction and lift increasing.

• Periodical: Applied Mechanics and Materials (Volume 461)
• Pages: 767-778
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.461.767
• Online since: November 2013
• Authors: Xue Peng Zhang, Yong Hua Wang, Lu Quan Ren
• Keywords: Airfoil, Bionic, Drag Reduction, Soft Surface

References

[1] Lucey A D，Carpenter P W. A numerical simulation of the interaction of a soft wall and inviscid flow [J]. Journal of Fluid Mechanics，1992，234: 121-146.

[2] Muralikrishnan R，Kumaran V. Experimental study of the in stability of the viscous flow past a soft surface [J]. Physics of Fluids，2002，14(2): 775-780.

DOI: 10.1063/1.1427923

[3] ZHAO Han-zhong.  Influence of soft wall on velocity profile deformation in a turbulent boundary layer [J]. Journal of Hydrodynamics, 2002, 17(4), 391-399.

[4] LEET，FISHERM，SCHWARZWH. Investigation of stable interaction of a passive soft surfacewith a turbu-lent boundary layer[J]. J. Fluid Mech，1993，257: 373-401.

[5] Choi K S，Yang X，Clayton B R，et al. Turbulent drag reduction using soft surface[J]. Proceedings of the Royal Society，1997，453: 2229-2240.

[6] WANG Yu-chun, JIANG Nan, ZHOU Xing-hua, SHU Wei. The Experimental Investigation of Coherent Structure Control in Turbulent Boundary Layer over Soft Wall [J]. Journal of Experimental Mechanicals, 2004, 19(1): 45-49.

[7] WANG Yu-chun, JIANG Nan, SHU Wei. Experimental Investigation of Drag Reduction Mechanism over Soft Wall and Multi-scale Coherent Structure Control in Turbulent Boundary Layer [J]. Journal of Experimental Mechanicals, 2005, 20(12): 21-25.

[8] ZHANG Qing-li, LI Jing-bo. Control of Boundary Layer Transition Using Active Soft Wall Motion [J]. Acta Aerodynamica Sinica, 1999, 7(3): 333-338.

[9] LI Wan-ping, Yang Xin-xiang. Test Research on Drag Reduction of Soft Wall [J]. Journal of Hydrodynamics, 1991, 6: 108-112.

[10] ZHANG Xiao-ci, ZHANG Jun, WANG Bao-zhu. Test on Drag Reduction of Soft Surface and Research of Drag Reduction Mechanism. Journal of Ship Mechanics, 2004, 8(4): 16-21.

[11] Cooper A J，Carpenter P W. The stability of rotating disc boundary-layer flow over a soft wall. Journal of Fluid Mechanics，1997，350（10）.