Anisotropic adaptive nearly body-fitted meshes for CFD

Abstract

This paper presents an anisotropic adaptive strategy for CFD that combines a nearly body-fitted mesh strategy with an iterative anisotropic adaptation to the flow solution. The nearly body-fitted mesh method consists in modelling embedded interfaces by a level-set representation in combination with local anisotropic mesh refinement and mesh adaptation (Quan et al. in Comput Methods Appl Mech Eng 268:65---81, 2014). The generated nearly body-fitted meshes are used to perform CFD simulations. Besides, anisotropic mesh adaptation based on the Hessian of the flow solution is used to improve the accuracy of the solution. We show that the method is beneficial in challenging CFD simulations involving complex geometries and time dependent flow, as it suppresses the need for the tedious process of body-fitted mesh generation, without altering the finite element formulation nor the prescription of boundary conditions. The methodology yields accurate flow solutions for a reasonable computational cost, despite very limited user interaction.