3-DIMENSIONAL NAVIER-STOKES FULL-POTENTIAL COUPLED ANALYSIS FOR VISCOUS TRANSONIC FLOW

A novel technique for the prediction of three-dimensional steady and u nsteady viscous flows past arbitrary configurations is described. The flowfield is partitioned into an inner region adjacent to the solid su rface and an outer region away from the solid surface. The solution pr ocedure uses a three-dimensional compressible Navier-Stokes solver in the inner vortical region and a three-dimensional unsteady full-potent ial now solver in the outer irrotational region. These two solvers are tightly coupled and integrated simultaneously in time. This coupled a nalysis enables efficient and accurate computation of transonic flows, including unsteady viscous effects. In the present work, details of t he coupling procedure are described, along with numerical validation o f the coupled formulation. Computational results are presented for an airplane wing as well as for a helicopter rotor in hover; these are co mpared with experimental data and other computational fluid dynamics d ata. The present coupled analysis requires only about 50% of the CPU t ime needed by a standard Navier-Stokes analysis and generates equally accurate data.