NUMERICAL VORTICITY CONFINEMENT FOR VORTEX SOLID BODY INTERACTION PROBLEMS

A new numerical method based on adding a term to the Euler/Navier-Stokes equations has demonstrated that it can effectively treat vortex dominated flows using low order numerical schemes and coarse grids. With the technique, numerical diffusion introduced by convection schemes can be eliminated when solving the modified flow governing equations. The modification of the velocity field, which conserves the total vorticity, essentially convects the vorticity toward its local extreme to offset the numerical diffusion. This method preserves the vortex structure even when vortices travel through a coarse grid region. The method is implemented separately with two distinctive basic solvers: a Navier-Stokes flow solver based on a vorticity-velocity formulation and an Euler solver based on a velocity-pressure formulation, Problems presented in this paper include airfoil dynamic stall, vortex-airfoil interaction, and vortex-fuselage interactions.