NUMERICAL-STUDIES OF SUPERSONIC-FLOW OVER A COMPRESSION CORNER

Numerical solutions of the Reynolds-averaged Navier-Stokes equations are presented for the shock/boundary-layer interaction which occurs with the attached, near-adiabatic, turbulent flow of air over a two-dimensional compression corner of 11-degrees at a Mach number of 2.5. It is shown that for this near-adiabatic flow, the isenthalpic and non-isenthalpic Navier-Stokes equations produce solutions which are very similar in respect of the velocity, pressure and density fields. In the first part of the work, two different upstream, or approaching boundary-layer profiles are considered: one with a normal full velocity profile and the other with a less full profile corresponding to a boundary layer that has developed in an adverse pressure gradient. Several turbulence models are compared using the isenthalpic form of the equations (because the computations are more economical). It is found that agreement with previous experiments (such as in the location of the shock and density profile predictions) is improved in the vicinity of the interaction using the non-equilibrium Johnson-King model compared to the equilibrium models of Baldwin-Lomax and Cebeci-Smith. The second part of the work examines the effects of turbulent Prandtl number (Pr(t)) modelling for this flow using the non-isenthalpic form of the Navier-Stokes equations. Three models for the turbulent Prandtl number are tested. It is found that modelling Pr(t) affects the velocity, pressure and density fields only very slightly, and that the main impact is on the prediction of temperatures very close to the wall. The adiabatic wall temperature variation through the interaction has been measured experimentally and compared with the predictions. The best agreement was obtained using Wassel and Catton's model for Pr(t) rather than the familiar assumption that Pr(t) = 0.9 everywhere in the flow.