Research on two equation models

The k-epsilon model is the most widely used turbulence model in engineering calculations. However, the model has several deficiencies that need to be fixed. This document presents improvements to the capabilities of the k-epsilon model in the following areas: a Galilean and tensorial invariant k-epsilon model for near wall turbulence; a new set of wall functions for attached flows; a new model equation for the dissipation rate, which has a better theoretical basis, contains the contribution of flow inhomogeneity, and captures the effect of the pressure gradient accurately; and a better model for bypass transition due to freestream turbulence.