Computational Fluid Dynamics Study Of Turbulence Modeling For An OGIVE Using Cobalt Flow Solver And A 2nd Tree-Based Cartesian Grid Generator

Abstract

A 2 n tree-based Cartesian grid generation method has been developed recently for complex geometries to simulate viscous flows. The "viscous" Cartesian grid is capable of resolving boundary layers with high-aspect ratio projected viscous layer grids. Compared with an Octree data structure, the 2 n tree data structure supports anisotropic grid adaptations in any of the coordinate directions in an arbitrary manner. This capability enables flow features such as shocks, shear layers, and wakes to be resolved very efficiently. In this paper, steady-state Navier-Stokes Computational Fluid Dynamics (CFD) analyses were performed on a cylindrical body Ogive using five different turbulence models in the commercial flow solver Cobalt with the 2 n based Cartesian grid generator. Turbulence models tested were the Spalart-Allmaras (SA), Menter-Shear-Stress Transport (SST), coupled Detached Eddy Simulation-Spalart-Allmaras (DES-SA), coupled Detached Eddy Simulation-Shear Stress Transport (DES-SST), and the κ-ω model. The geometry model consisted of a 3-caliber nose with a cubic profile followed by a 10 caliber cylindrical body. Surface pressures and off body vortex flows were computed and compared to well documented experimental results for a test case at Mach 2.4 and 14° Angle-Of-Attack (AOA). Overall results showed that all turbulence models compared well with experimental with κ-ω giving the best results.