An Effective Approach to Computation of Forces in Viscous Incompressible Flows

In the paper we present an effective method to compute forces in external flows of viscous incompressible fluids. It is an extension of the variational approach proposed initially by Quartapelle and Napolitano (1983, AIAA J. 21, 911) and is particularly well adapted to the case where a vortex method is used to solve the hydrodynamic problem. The derived formula involves a harmonic function η and a convenient method for its determination is also shown. The effectiveness of the presented approach is confirmed by computational examples.