Experimental and numerical study of parametric dependence of lift in flapping flight

Abstract

Flapping wings exhibit better performance than the fixed wings as the size of the flying objects decrease. In nature flight by the flapping wings is predominant in case of insects and small birds. Motivated by this aspect engineers have been trying to devise Micro Air Vehicles (MAV) using flapping wings. Many interesting phenomena like delayed stall, leading edge vortex, wake cap- ture etc., have been suggested as mechanism of lift generation & enhancers in the case of insect flapping flight. Our focus is on impact of asymmetry in upstroke speed and downstroke speed in lift generation and parametric study to find the optimum wing kinematics. Both experimental st- udy using mechanical models and numerical simulations by using the Discrete Vortex Method (DVM) have been done to find the efficacy of this mechanism in lift generation. Influence of ki- nematic parameters like inclination of the mean position of the wings, amplitude and asymmetry ratio have been studied through numerical simulations. A brief study have been done to explore the impact of flexibility on lift generation through simulations.