Hello!
I'm currently using COMSOL for a 3D microfluidics problem and I am performing a mesh refinement study. As I am quite new on the subject, I am only using different element sizes for a default mesh, and going through some of the sizes. So I have some questions about this:
1) Are these default meshes good enough for a two phase flow problem? I've seen in literature that quadrilateral (cubic in 3D) are use in such studies if the mesh is mentioned in the first place.
2) I started by using the 'Coarse' mesh and went all the to the 'Finer' one. I notived that COMSOL used PARDISO to solve the problem when the mesh was 'Coarse', 'Normal' and 'Fine', and the results were getting closer, as expected. However, GMRES was used with the 'Finer' mesh, and the results were a bit different. I was monitoring the fluid velocity at different points and in two plots, the velocity was quite higher than the two preivous ones. So I was wondering if the solver has any effect on the result, and how can I make COMSOL use PARDISO so I can be coherent all the way.