Numerical study of rigid and flexible wing shapes in hover

Abstract

This study is focused on evaluating the aerodynamic performance of rigid and isotropic flexible wing shapes defined by the radius of the first moment of wing area (r1) at Reynolds number of 6000. An immersed boundary method was used to solve the 3D, viscous, incompressible Navier-Stokes equations, and coupled with an in-house non-linear finite element solver for fluid structure interaction simulations. Numerical simulations of flexible r1= 0.43, 0.53 and 0.63 wing shapes performed with a single degree of freedom flapping shows that thrust and peak lift coefficients increase with r1. Higher thrust in the r1 = 0.63 wing is attributed to the large induced pitch angle, and higher peak lift (compared to the rigid counterpart) results from an increase in the stroke amplitude and spanwise deformation of the wing that anchors the leading edge vortex.