EFFECT OF TRAILING EDGE GEOMETRY ON THE FLUID-STRUCTURE INTERACTION OF PITCHING FOILS

Abstract

In this thesis, a numerical study on the fluid-structure interaction of a pitching foil immersed in a uniform flow is performed for a range of geometric and physical parameters. A three-dimensional variational framework, coupling an unsteady incompressible turbulent fluid solver and a flexible multibody structural solver is employed for the coupled fluid-structure analysis. The reference geometry for the foil is a square with an aspect ratio AR=1. By modifying the trailing edge angle two others geometries, with an inward and outward trailing edge, are considered for the coupled dynamical analysis. The leading edge and the surface area of the foil are considered constant between the three studied geometries, and thus we focus completely on the effect of the trailing edge shape. Of particular interest is to analyze the downstream wake topology, the temporal and averaged evolution of the propulsive performance, and the constraints sustained by a pitching foil for the considered trailing edge angles, for different flexural rigidities and for a range of Strouhal numbers.