MORKOVIN HYPOTHESIS AND THE MODELING OF WALL-BOUNDED COMPRESSIBLE TURBULENT FLOWS

Modeling of compressible wall-bounded turbulent flows relies on the hy pothesis of Morkovin, who suggested that compressibility effects on tu rbulence could be accounted for by the mean density variations alone. This hypothesis has been shown to yield good results for the mean velo city and mean temperature fields when the incompressible turbulence mo dels are extended directly to calculate compressible turbulent boundar y layers. However, its applicability for the turbulence field has been less closely scrutinized. The reason is the lack of sufficiently deta iled compressible turbulence data for comparison. Such data are now be coming available. Therefore, the purpose here is to assess the applica bility of the Morkovin hypothesis to the turbulence field using direct numerical simulation data of a supersonic, flat plate boundary layer A near-wall Reynolds-stress closure based on a quasi-linear pressure-s train model is used to calculate this supersonic, boundary-layer flow. Comparisons between calculations and direct numerical simulation data show that the Morkovin hypothesis is just as applicable for the turbu lence field and there is a dynamic similarity between the near-wall tu rbulence field of an incompressible and a compressible wall-bounded tu rbulent flow, In addition, the validation of this model is reported fo r compressible flow calculations covering a wide range of Mach numbers with adiabatic and constant-temperature wall boundary conditions, The se results show that the model yields good predictions of Bat-plate tu rbulent boundary layers up to a Mach number of 10.31.