Supersonic Turbulent Boundary Layer with Pressure Gradients

Abstract

The current work presents computational studies of a compressible boundary layer in the presence of non zero pressure gradients. The aim of this investigation is to study and analyse the behaviour of near-wall compressible flows under the effects of both favourable and adverse pressure gradients. Results are reported using two alternative two-equation turbulence closures and a second order closure in order to provide an evaluation of the various models. These calculations, conducted through the boundary layer, have allowed a better understanding of the mechanisms controlling this kind of flow. The effects of streamwise pressure gradients on the mean and turbulent quantities and on the turbulence anisotropy, are studied, particularly in the viscous sublayer. It is concluded that there are a specific pressure gradient effects present in the bondary layer. The results of the analysis show that the effects found in incompressible flows are also present in this case, and have been qualitatively reproduced. There are, in addition, other influences due to the compressibility. From a comparative analysis with the various models, we find that the results with the Chien model containing the Nichols correction gave a better prediction than Chien model under a favourable pressure gradient.