ABSTRACT
A zonal solution procedure for unsteady viscous flows is described. This procedure confines the solution field to the viscous part of the flow and then computes each of the several coexisting viscous zones
the boundary layers, the recirculating regions, the wake and the trailing vortices, including tip vortices-independently without iterative matching of these zones. The procedure is established using an integral formulation which contains domain integrals as well as boundary integrals. It is demonstrated conclusively that the procedure is ideally suited for unsteady viscous flows involving either two or three spatial dimensions for a broad range of applications. Under general circumstances, the procedure produces remarkably accurate results with minimal computational effort. Under special circumstances, the domain integral in the formulation vanishes and the procedure reduces to one resembling well-known field panel methods. Selected numerical results for problems offish swimming, dynamic stall of oscillating aerofoils and flow over wings of finite span are presented to illustrate the applications of the procedure.
