Computational Investigation of 3D Turbulent Flow Separation around a Spheroid using an Unstructured Grid Method

Laminar and turbulent separated flows around a 6 : 1 prolate spheroid are investigated using an unstructured grid CFD method. The RANS equations are solved for incompressible viscous flows. The artificial compressibility is introduced in the continuity equation and cell-centered finite-volume method on unstructured grid is used for spatial discretization. The Spalart-Allmaras one-equation turbulence model is employed for the Reynolds stress. The computational results are compared with experimental data and the physics of three-dimensional turbulent flow separation is confirmed. A range of Reynolds numbers and angles of attack is considered and the effects are investigated. The modification of the Spalart-Allmaras model is added to improve the performance and examine the effects of turbulence model on the vortical flow structure.