Current capabilities for modelling turbulence in industrial flows

This paper summarizes some of the more widely applied or promising schemes for computing heat and momentum transport in industrially relevant flows. Such flows typically involve complex flow domains, severe pressure gradients and regions of flow separation and reattachment. Models tuned by reference to equilibrium, simple shear flows cannot in general be relied upon to predict accurately the effects of these complexities on the transport processes. The main conclusions drawn are that second-moment closure offers a far more reliable basis for computing non-equilibrium turbulent flows than eddy-viscosity schemes, especially in flows with very complex strain fields or those substantially affected by external force fields. Moreover, where significant variations in shear stress occur across the near-wall viscosity-affected sublayer, the usual practice of employing wall functions needs to be replaced by at least a two-equation model in order to capture, even qualitatively, the consequent effects on wall heat transfer or skin friction coefficient.