Application of non-linear eddy-viscosity model involving a2 stress-invariant transport equation to transitional flows

Abstract

This paper presents an effort to model the boundary layer separation-induced transition on a flat plate with a semi-circular leading edge. The modeling is performed using the three-equation non-linear eddy-viscosity model of Craft et al. (1997), where the third equation refers to the transport of the anisotropy stress invariant A2. The three-equation model is shown to generate quite realistic results, since it is able to capture the transition mechanism by predicting correctly the transition length, and by reproducing with good accuracy both the velocity and u-RMS distributions inside the separated pre-transitional, transitional, and fully turbulent boundary layer. This observation is supported also by the very accurate predictions of the skin friction coefficient and shape factor boundary layer integral parameter, especially for cases with moderate freestream turbulence intensity. © 2013 Taylor and Francis Group LLC.