Numerical Modeling of Hypersonic Weakly Ionized External Flowfields with Poisson’s Equation

Abstract

A seven-species air model is used to numerically simulate and analyze the flowfield of an air plasma. Previous numerical models have employed different electric field approximations that assume ambipolar diffusion theory. The objective of this new model is to increase the accuracy of the numerical simulations by solving the Poisson’s equation for calculating the electric field and replacing the ambipolar diffusion assumption by solving the momentum conservation equations of charged particles. This new approach removes the assumptions of an equilibrium electric field and the ambipolar diffusion used in many previous computational fluid dynamics studies for the hypersonic, nonequilibrium flows with a weakly ionized plasma. A new model was created to capture the charge separation effect across the shock wave. Additionally, it shown that the heat flux at the wall could by underpredicted by as much as 31% along the wall.