Accuracy Tests for COMSOL - and Delaunay Meshes
Ekkehard O. Holzbecher, Hang Si · 2008
In the paper we examine the accuracy of various meshes for different model regions and simple differential equations in 2D and in 3D. We study the potential equation for a single irregular domain (2D testcase 1), for a simple domain with irregular sub-domains (2D testcase 2) and a 3D testcase. For testcase 1 we compare with the analytical solution, for testcases 2 with the best solution, obtained by several adaptive grid refinements on a fine mesh. We study meshes obtained by global refinements and by adaptive grid refinement, using various options available in COMSOL Multiphysics. For quadratic elements we find convergence rates between 1 and 1.5, i.e. significantly reduced in comparison to the theoretical rate. Moreover, for testcase 1 we examine imported meshes with Delaunay property and find no advantages in comparison to non-Delaunay meshes for the chosen set-up.