Numerical study of the wall shear stress produced by the impingement of a plane turbulent jet on a plate

The present investigation has been carried out in the framework of the numerical studies of the wall function influence on the calculation of wall shear stress. This shear stress is generated by the action of a normal plane impinging jet on a flat plate. The Navier-Stokes, continuity and energy equations are solved for a two-dimensional turbulent compressible flow by using the finite volume method. The standard k-epsilon turbulence model is used as a closure model. To take into account the external shape influence of the nozzle, a quasi-orthogonal curvilinear mesh is used. For a suitable calculation of the wall shear stress, the classical logarithmic wall law and its generalized form are used. The results of these calculations depend on the near wall grid. Therefore, this influence of near wall grid is studied more specifically here. A hybrid wall law is proposed, which results from the simultaneous use of the classical logarithmic wall law and the generalized one. This hybrid law gives suitable shear stress distributions with less dependence on the near wall grid. The calculations are validated through experimental data.