A Scale Adaptive Simulation Model using Two-Equation Models

Abstract

The Scale-Adaptive Simulation (SAS) concept is based on the introduction of the von Karman length-scale into the turbulence scale equation. The information provided by the von Karman length-scale allows SAS models to dynamically adjust to resolved structures in a URANS simulation, which results in a LES-like behavior in unsteady regions of the flowfield. At the same time, the model provides standard RANS capabilities in stable flow regions. The introduction of the von Karman length-scale is based on the reformulation of Rottas’s equation for the integral length-scale. In the current paper, the term containing the von Karman length-scale is transformed to the SST turbulence model. It allows the SST model to be operated in a SAS mode.