PREDICTION OF TURBULENT TRANSITIONAL PHENOMENA WITH A NONLINEAR EDDY-VISCOSITY MODEL

This paper describes a new nonlinear eddy-viscosity model of turbulenc e designed with a view to predicting flow far from equilibrium, includ ing transition. The scheme follows earlier UMIST practice in adopting a cubic relation between the stress and the strain/vorticity tensors b ut broadens the range of flows to which the model applies by including a third transport equation for an anisotropy parameter of the stress field. Applications are shown for transition on a flat plate at differ ent levels of free-stream turbulence, for the normal impingement of a turbulent jet on a flat plate, and for the flow around a turbine blade . The model is shown to generate much more realistic predictions than what is said to be the best of the linear eddy-viscosity schemes. (C) 1997 by Elsevier Science Inc.