COMPOSITE, NAVIER-STOKES AND ENTER UNSTEADY-FLOW COMPUTATIONS IN BOUNDARY-LAYERS

Computational approaches based on previous nonlinear theoretical findi ngs are developed for a Composite system, the Navier-Stokes system, an d the Euler system of equations, in turn, with applications to incompr essible boundary-layer transition and dynamic stall. The emphasis is o n schemes appropriate for medium-to-large Reynolds numbers, and so as a start the computations are kept to two spatial dimensions. The Compo site scheme is developed first, including significant normal-pressure- gradient effects as suggested by the theory. The same scheme is then m odified to accommodate, iteratively, the Navier-Stokes form and then t he Euler form, for comparison. The agreement between the three sets of results tends to be very close in the parameter ranges studied. The n ecessary extensions of the work are also discussed.