Progress in turbulence modelling for incompressible flows

The paper reviews the currently available models for calculating turbulent stresses and heat or mass fluxes in incompressible flow and reports on progress made in replacing the Prandtl mixing-length hypothesis by more generally applicable models. These include models employing transport equations for the intensity and the length scale of the turbulent motion, notably the k-epsilon model, as well as second order closure schemes based on transport equations for the turbulent stresses and heat or mass fluxes themselves. The individual models are described briefly, their merits and demerits are discussed, and typical examples of calculations relevant to aerospace problems are presented.