Linear and nonlinear lift frequency response of a pitching membrane wing at low Reynolds numbers

Abstract

A linear state-space reduced-order model for the lift generated by a two-dimensional pitching membrane at low Reynolds numbers is presented. The framework couples an unsteady aerodynamic model for the aerodynamic loads generated by rigid pitching and by the flexible degrees of freedom of the wing with a linear structural membrane equation. The lift frequency response of the pitching membrane with respect to the membrane’s structural parameters is investigated, comparing the results with the response of a rigid wing. The analysis is extended by taking into account nonlinear structural effects using a harmonic balance method in the frequency domain. The nonlinear lift frequency response is obt..