MODELING ENGINEERING FLOWS WITH REYNOLDS STRESS TURBULENCE CLOSURE

A Reynolds stress model consists of differential or algebraic equations each governing the balance between generation, dissipation, redistribution and transport of a related Reynolds stress. More generally, "second-moment closure" combines the above stress equations with additional transport equations for heat or scalar fluxes. This paper argues the potential advantages of using such closures in preference to eddy viscosity models in the presence of recirculation, swirl and buoyancy. Some basic forms of Reynolds stress closure are introduced and their numerical implementation is outlined. Results are then presented for five out of some eighteen complex flow types computed at UMIST over the past six years. These demonstrate that significant improvements in predictive accuracy can be achieved in flows containing large recirculation regions and involving swirl. In all cases, such improvements appear to be rooted in the ability of the closures to mimic the strong response of the turbulence structure to streamline curvature. © 1990.