Learning Forum

[nickolas.giacomitti]

Hello, CFD_Friend! Thanks for your answer!

I have made a series of mesh refinement starting in a coarse mesh and refining in small increments, but every other parameter (temperature distribution, velocity, mass and energy ballance, heat flux) are stable in every mesh refinement I have done, the only parameter that have changed significantly is the "walls total heat flux".

For the tests that I have done, improoving mesh quality (skewness and orthogonality) does not change the reduction in "walls total heat flux" across mesh refinements.

In the table below are the results for mesh quality trough the iterations of mesh refinement, note that the simulation with the worst mesh quality parameters (in green) resulted in more accurate results compared with the analytical aproatch and compared with the other mesh iterations. In the same table you can see that the finer the mesh, lower is the delta heat flux, witch is the "walls total heat flux". It is possible to verify that, for the first 4 mesh refinements, the skewness and ortogonality did not change but the "walls total heat flux" (Delta heat flux (w/m²)) have reduced significantly with other parameters like temperature distribution, heat flux, stream velocity, mass and energy ballance results are in par (with certan error) with the analytical approach.

As for my tests, lower delta heat flux is correlated with grater simulation precision and/or resolution but I canot prove it by any documentation, and in a certain way does not make sanse when we see that the unity is w/m², therefore this value should not change with the mesh refinement because the superficial area of the 3D body must be rougthly the same across mesh refinement.

Do you have any more thogths to this matter?