Study of preconditioning methods applied to flowfield at all speeds

The preconditioning methods are used for solving two-dimensional compressible Navier-Stokes equations and an all-speed flow field numerical simulation method which can be used for both low-speed flows and compressible flows is developed. Ausm family schemes and multi-step Runge-Kutta time marching method are utilized to discretize Navier-Stokes equations. Numerical simulation results of flow field of a Bump, RAE2822 airfoil and multi-element high lift airfoil at different speeds are presented and are compared with the experimental data. The results showed that the calculation data based on preconditioning method are consistent with experimental data, and the convergence speed and accuracy are greatly improved, indicating the work of present paper has great practical significance.