THE FORCES ACTING ON AN OBSTACLE IN STRATIFIED FLOW

The three-dimensional steady flow of a heavy incompressible ideal flui d past an obstacle with a rigid boundary with general restrictions on the density and velocity distributions of the incident flow is conside red. A set of two non-linear second-order equations which describe the flow pattern is derived. Formulation of the boundary-value problem is discussed. Formulae for calculating the forces acting on the obstacle are derived. The simplifying assumptions associated with approximatin g the obstacle by a system of dipoles distributed over the barrier sur face are investigated. As an example, the flow of an unbounded exponen tially stratified fluid around a sphere is considered. Assuming the st ratification parameter to be small, the main term in the asymptotic fo rmula which expresses the dependence of the resistance on the sphere r adius and the stratification parameters is calculated.