Hi Experts, I have simulated a Conjugate HT problem. That worked fine but results were little away from analytical calculations. The need was to refine the fluid mesh. So I refined the fluid mesh and coupled unchanged solids to it. Then I am facing the problem of convergence in solids. I tried reducing the under relaxation factor for fluid and solids independantly, but in vain. How can I solve this problem? help requested.

You cannot have couples between fluid and solid interfaces. They must match vertex to vertex. You should also starlink with double precision.