Parallel implicit Multigrid Method for Direct Numerical Simulation of Time-Dependent Compressible Turbulent Flow Around Flight Vehicles
Technical rept. 1 Mar 97 30 Sep 98
LOUISIANA TECH UNIV RUSTON
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An oblique transition process of a flat-plate boundary layer at a free-stream Mach number of M infinity 4.5 and a Reynolds number of 10000 based on free-stream velocity and inflow displacement thickness is simulated as the validation of the code. Four transitional stages are observed the linear and weakly nonlinear growth, the appearance of staggered A-vortex patterns, the evolution of A-vortex into hairpin vortex, the breakdown of hairpin vortical structures. The evolution of averaged quantities, such as the skin-friction coefficient, the mean velocity profile, the boundary layer thickness are all computed and found agreed very well with theoretic and experimental results. For complex geometry, 2D and 3D numerical grid generation method are used to generate high-quality meshes. Subsonic flow around 2D NACA 0012 airfoil and 3D Delta wing with a large angle of attack are investigated with large eddy simulation. Flow separations and large eddy structures are observed, the interactions between vortical structures will be studied.
- Fluid Mechanics