THE HOMOGENEOUS BOUNDARY LAYER AT AT AXISYMMETRIC STAGNATION POINT WITH LARGE RATES OF INJECTION

摘要

This report presents a theoretical analysis of the boundary layer at an axisymmetric stagnation point with large rates of air injection. The results of a previous investigation indicated that for localized mass trans¬fer in the stagnation region, the rates of injection are considerably greater than those usually treated. The exact stagnation point boundary layer equa¬tion are integrated numerically for an approximate representation of the gas properties. The two point boundary conditions are treated in a new manner which is useful for various boundary layer and mixing problems. The exact solutions indicate that for large rates of injection the boundary layer is closely represented by an inner isothermal shear flow and by an exterior, relatively thin region, in which the flow variables change to their free-stream values. An integral method based on profiles suggested by the exact solutions is developed and shown to lead to accurate predictions of the integral thicknesses which are of interest for a study of the down¬stream influence of the stagnation point mass transfer.