why hex-dominant mesh does not work in CHT first version. I know it des not support in CHT second version?
The CHT solvers need conformal meshes at the interfaces, which can only be currently achieved with the Standard mesher.
Conformal = meshes of the coinciding faces have nodes located exactly at the same location. This is required for precise computation of the heat transfer at the interfaces.
If I choose incompressible flow, then can I use hex dominant mesh ?
Yes, you should be able. Please try it and report back!
Ok, I will do.
Usually, I apply CHT for heat transfer simulation. However, due to no structured mesh in CHT v2, which one I can apply?
The recommendation is to use CHT v2 with the non structured mesh.
However, how can I prove the quality of mesh?
because everywhere it is written structured mesh is high quality mesh
another thing is, I only noticed that CHT v1 has hex dominant mesh function but it does not work again.
why it is appeared in function if it is not available or does not work?
Why recommendation is to use when structured mesh has a high quality?
Our standard mesher is a mixed mesh: triangular elements are used on the surfaces to have the better representation, but at the core of the volumes there is always hexahedral elements. This increase the quality of the results with respect to a pure tetrahedral mesh.
In order to assure the quality of the results, you must perform validations and mesh independence analysis.
I suggest implementing a warning regarding this aspect (mesh conformity in the interphases), before allowing to launch a simulation. By the way, was this requirement (use of standard mesh) in the CHT guidelines?
Also, in the future, implementing arbitrary mesh interface (AMI), as it is already available for CHT in OpenFOAM. https://www.esi-group.com/sites/default/files/resource/other/2544/2020-07-14-SVU-CFD-RE-B_AeroVehicule_Abstract.pdf
it was not requirement but advised because structured mesh has better quality