Applying a preconditioning technique to the euler equations to accelerate the convergence rate for low-speed flows

Abstract

© 2019, Avestia Publishing.In an effort to ensure the robustness and numerical stability of a three-dimensional explicit compressible code for all speed flows, a preconditioning technique was implemented. The code solves Euler steady-state equations into a three-dimensional flow. Local preconditioning was implemented due to their accuracy in predicting lift and drag forces on mixed flows. However, for low speed flows near stagnation points numerical perturbations are amplified, generating a loss in the convergence rate, code accuracy and robustness. Aiming to improve the preconditioning accuracy and convergence rate suggested a new limit to the preconditioning sensor based on the flow pressure. Numerical simulations of a subsonic flow over a cylinder showed a faster convergence rate when the preconditioning technique was implemented.

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