Abonnement à la biblothèque: Guest
TSFP DL Home Archives Comité de direction

ONE-EQUATION SUBGRID SCALE MODEL FOR LARGE EDDY SIMULATION OF WEAKLY COMPRESSIBLE FLOW

Changhwa Han
Department of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan

Takeo Kajishima
Department of Mechanical Engineering, Osaka University, 2-1 Yamada-oka, Suita-city, Osaka 565-0871 Japan

Résumé

In this study, we are developing a large eddy simulation (LES) method suitable for the analysis of flow and aerodynamic noise source. Applications include low Mach number flows around a large-scale wind turbine blade, an aircraft at takeoff and landing, or high-speed trains. We improved a one-equation subgrid scale (SGS) model to take into account non-equilibrium and flow separation. It is incorporated into the computational scheme that modifies the pressure equation to deal with weakly compressible flows. Particularly, a coherent structure model proposed by Kobayashi (2005) was successfully incorporated into the energy production rate of SGS kinetic energy. A flow around the NACA0012 airfoil was simulated by this new method. The computational results such as the time averaged pressure coefficient and pressure fluctuation are in reasonable agreement with the experimental data by Miyazawa et. al. (2003). In addition, a characteristic density fluctuation, which might be related to the sound source, was captured in the separation near the leading edge.