Wall-normal-free Reynolds-stress closure for three-dimensional compressible separated flows

A near-wall Reynolds-stress closure that is independent of the distance fro m the wall and of the normal to the wall direction is developed and validat ed. Particular attention was given in the applicability of the model to com plex three-dimensional flows with shock waves and boundary-layer separation . In the separated flow region, measurements and model computations indicat e that the flatness parameter A of the anisotropy tensor a(ij) approaches u nity. Therefore, control of separation is achieved in the model through the particular functional dependence of the rapid pressure-strain isotropizati on of production model coefficient on A. Echo terms are treated by replacin g geometric normals and distances by functions of the gradients of turbulen ce length scale and anisotropy tensor invariants. The model is initially co mpared with measurements for compressible flat-plate boundary-layer flows. It is then validated by comparison with experimental data in a two-dimensio nal compression corner oblique shock-wave/boundary-layer interaction at Mac h 3. Finally the model is applied to the computation of the three-dimension al interaction of a Mach 1.5-1.8 strong shock wave with the boundary layers of a rectangular channel fitted with a swept bump on the lower wall, and r esults are compared with measurements. One important advantage of the propo sed model is its robustness in complex three-dimensional flows. A detailed discussion of the range of validity of the model and possible improvements is presented.