Reimplementation of K−omega SST DDES Model in Code_Saturne for GTS Model Aerodynamics

Abstract

The development of hybrid turbulence models addresses some limitations of Reynolds-Averaged Navier–Stokes (RANS) models while avoiding the prohibitive computational cost of Large Eddy Simulation (LES), particularly at high Reynolds numbers. Motivated by the need for an accurate resolution of the near-wall flow around the Ground Transportation System (GTS) vehicle model at various yaw angles, and using the CFD software Code_Saturne®, the reimplementation and parameter tuning of the k-omega SST DDES (Delayed Detached-Eddy Simulation) turbulence model, originally formulated based on the Spalart-Allmaras model, is proposed, along with the implementation of the k-omega SST IDDES (Improved Delayed Detached-Eddy Simulation) model. Parameter tuning is conducted to achieve agreement with experimental results from the case under study. These modifications minimize the grid-induced separation (GIS) phenomenon and improve the prediction of force coefficients and friction coefficient curves.