Abstract:

The features of dragand noisereduction of the representative animal owls in fluid medium were studied. It was found that the silent flight capability to the prey of the long-eared owl mainly depends upon the distinct sequential array of its high-lift wing feathers. Applying the reverse reconstruction technique to quantify the geometric information about the leading edge shape of the long-eared owl wing, a bionic coupled model was built in which the leading edge shape was defined by wavelength and wavecrest-to-wavetrough amplitude. The finite volume method and the pressurecorrected SIMPLEC algorithm were used to simulate numerically the aerodynamic performance of the bionic airfoil model. The results show that at the condition of deep stall, the bionic airfoil model can improve significantly the aeroperformance in a certain ranges of wavelength and amplitude, increase the airfoil lift by 19.8%, delay the stall attach angle by 30.3%. The amplitude of the airfoil leading edge demonstrates more effective on improving the aeroperformance of airfoil at deep-stall than that of wavelength.

Key words: engineering bionics, wing, sequential array, long-eared owl, leading edge feature, bionic coupling