PRESSURE FORCES ON DEFORMABLE BODIES IN NON-UNIFORM INVISCID FLOWS

Abstract

The problem of a general deformable shape moving unsteadily with six degrees of freedom in a non-homogeneous flow field is studied here in some detail. First we derive the force-balance equation for a deformable spherical shape moving in an arbitrary non-uniform irrotational flow. These results are then extended for elongated shapes, of a prolate spheroidal type, by including the effect of the angular velocity of the body. It is also demonstrated how to obtain expressions for the force in the case of an arbitrary body moving in a weakly non-uniform flow. The results apply to both irrotational and rotational flows, provided the mean vorticity of the ambient flow is considered small for all times.