INVESTIGATION OF NONLINEAR TRANSITION MECHANISMS IN BOUNDARY-LAYER FLOWS BY NUMERICAL SOLUTION OF THE NAVIER-STOKES EQUATIONS.

The present investigations are based on a direct numerical approach, i. e. , bypassing the formulation of eigenvalue problems as is customary in hydrodynamic stability theory. Rather, a rectangular integration domain A-B-C-D is selected whereby the disturbances are introduced at the upstream boundary A-D. The reaction of the flow to the disturbances introduced at A-D is then determined by numerical solution of the complete Navier-Stokes equations for two-dimensional incompressible flow. Therefore, the downstream development of the disturbances can be studied. 6 refs.