On the a Posteriori Error Estimation in Mesh Adaptation to Improve CFD Solutions

uring a typical CFD analysis, a large effort is devoted to the mesh generation process. Not only is mesh generation time consuming, but also the resulting mesh may not be completely appropriate to sufficiently resolve all the details of the flow. Mesh adaptation methodology is a powerful tool, not only to improve solver accuracy but also to allow simulations starting from an arbitrarily coarse initial grid. In Refs.1,2, a robust and efficient 3D automatic mesh adaptation methodology, with CAD integrity, OptiGrid, has been developed. The adaptation procedure uses an a posteriori interpolation error estimate, whose magnitude and direction are controlled by the matrix of local second derivatives of a selected flow variable. This error is projected over the mesh edges, and drives the nodal movement algorithm, as well as the edge refinement, coarsening and face swapping strategies. Very good results have been obtained using this mesh approach.