A Wall-Distance-Free k-ε Model With Enhanced Near-Wall Treatment

Abstract

This paper evaluates a wall-distance-free low-Re k-ε turbulence closure model which incorporates an extra source term in the ε transport equation designed to increase the level of ε in nonequilibrium flow regions, thus reducing the kinetic energy and length scale magnitudes to improve prediction of adverse pressure gradient flows, including those involving separated flows regions. Two such cases are used here to test the model: one in the low speed flow regime, the other a supersonic one. Comparisons with experimental data and with an earlier version of the k-ε model, as well as with a variant of the k-ω model (both also wall-distance-free) reveal that the proposed model enables improved prediction of adverse pressure gradient flows relative to more traditional k-ε models.