Bionic simulation of double clap-and-fling wing mechanism with SPH FSI method

Abstract

Three-dimensional numerical simulations of flexible flapping wings based on the fluid-structure interaction in biological and bioinspired flow have become a vibrant and challenging research topic. The present paper focuses on a parametric study of the aerodynamic performance of a bionic flexible clapping wing. The proposed model deforms the wing in spanwise and chordwise directions based on the six rigid bodies connected along the wing veins using ball links and springs. Unsteady effects of
flapping wing micro air vehicles with a double clap-fling configuration are investigated using an air-solid interaction model based on smoothed particle hydrodynamics and rigid multi-body dynamics. A validation experiment determined the convergence conditions and computational model accuracy. The proposed numerical model is evaluated in terms of flexible variation law and aerodynamic performance. The results indicate that the flapping frequency, angle of attack, and wind velocity significantly influence the lift. Furthermore, increasing the frequency will monotonically expand the maximum and time-averaged lift curve values. When the angle of attack is less than 30 degrees, the influence on the time-averaged and maximum lift is proportional to the angle of attack. When the angle of attack is larger than 45 degrees, a stall-like condition is detected. To broaden the applicability of the present findings, a dimensionless parameter, reduced frequency, is defined, and its influence on the maximum and time-averaged lift is investigated. This parametric study shows that as the reduced frequency increases, the maximum and time-averaged lift increases and then decreases. The present study could reach a modeling framework that better explains the clapping wing aerodynamics.