Experimental and Computational Study on Rotational Lift Production of Insect Flapping Wing

This paper presents an investigation of the rotational lift production of translating and rotating wings within a small insect’s Reynolds numbers range. Using the Reynolds number 1200 of a bumble bee, three wing section profiles are studied; a circular cylinder model as the reference of a blunt body for which the well known Magnus effect will occur, a flat plate model as the reference of a sharp body for which the Kramer effect will occur and finally, an elliptical cylinder model, as a transition case. Direct force measurement and the particle image velocimetry (PIV) experiment have been performed in order to measure the lift produced and to bring out the surrounding flow velocity. The Kutta-Joukowski theorem has been applied on the PIV results. The experimental results are analyzed and verified with the comparison of computational results. In general, there is a reasonable agreement between the experimental and computational results. The results confirm that Magnus effect has been effectively observed for the circular cylinder model and no Kramer effect is observed for the flat plate model. Finally, the elliptical cylinder model appears not to be blunt enough for the Magnus effect to occur and not to be sharp enough for the Kramer effect to occur.