Application of a three-equation cubic eddy viscosity model to 3-D turbulent flows by the unstructured grid method

The three-equation cubic k-ε-A₂ model proposed by Craft et al. (Int. J. Heat Fluid Flow 18 (1997) 15-28) is evaluated in three-dimensional (3-D) turbulent flows pertinent to engineering applications, especially in the automobile industry. For the computations of complex industrial flows, a numerical scheme has been developed using the cell vertex unstructured grid method. This scheme treats a mixture of tetrahedral, pyramidal, prismatic and hexahedral computational cells with high accuracy. The industrial flows chosen are internal combustion (IC) engine port-cylinder flows and flows around aerodynamic bluff bodies. The model performance in U-bend duct flows and a flow around a surface-mounted cubical obstacle is also examined. These fundamental flows include essential features of the industrial flows presently focused on. The model performs generally satisfactorily. However, the performance in a 3-D separating wake flow behind a bluff body suggests that the model needs further improvements.