Laminar boundary-layer reattachment in supersonic flow. Part 2. Numerical solution

A possible model of the flow in the neighbourhood of a point of reattachment of a supersonic laminar boundary layer consists of a three-tiered ‘triple-deck’ structure in which the basic problem reduces to that of solving the incompressible boundary-layer equations in the lower deck, a region of lateral and streamwise extent $O(R^{-\frac{5}{8}})$ and $O(R^{-\frac{3}{8}})$ , where R is a representative Reynolds number of the flow (Daniels 1979). The present paper describes a scheme for the numerical solution of this problem which provides evidence in support of the proposed model and quantitative values for the O(R−¼) correction to the base pressure in the flow upstream and the O(R−⅝) correction to the position of reattachment relative to the point of intersection of the incoming shear layer and the wall. An important feature of the scheme is that it copes successfully with a flow which contains substantial reverse velocities.