Comparison of Turbulence Models Applied to Backward-Facing Step Flow.

Abstract

In our previous work, we have already computed backward-facing step flow using large eddy simulation (LES) and obtained satisfactory results in comparison to experimental data. In this work, the behavior of time-averaged turbulence models and the influence of the diffusion model in the turbulent energy equation are investigated using the LES database. It is found that the algebraic stress model describes this flow more accurately than the eddy viscosity model, and that the gradient-diffusion model for the turbulent diffusion term cannot accurately predict the turbulent energy distribution in the recirculating region. A new diffusion model using TSDIA theory is applied and the relationship between the reattachment length and the turbulent energy distribution in the recirculating region is discussed.