dynamicRefineFvMesh creates polyhedra from hex mesh?
 

Good afternoon.

I am connecting the dynamicRefineFvMesh library to a custom solver to expand adaptive mesh refinement capability. When I start with a mesh composed entirely of hexahedra (generated by blockMesh), the refinement code eventually introduces polyhedra with many faces... up to 21 faces.

Does anyone have an explanation for why this happens? I thought the refinement code only worked with hex cells, and called the hexRef8 cutter to create 8 child hex cells from a parent hex cell.

Thanks for any insight.

Hi everyone,


I figured this out. What happened was that when a parent cell was refined to 8 child cells, the neighbor, un-refined cell is now counted as having 9 faces (the five original faces, plus the shared face now split into four faces). When a un-refined cell shares multiple faces with refined cells, this happens again, causing checkMesh to count these cells as polyhedra with number of faces as multiples of three.


Further, when visualizing in Paraview with the Decompose Polyhedra box checked (default option), these hex cells were decomposed into pyramid and prism type cells, leading me to believe there were non hexes in the mesh.

Decompose Polyhedra on:


https://www.cfd-online.com/Forums/me...decomppoly.png


Decompose Polyhedra off:


https://www.cfd-online.com/Forums/me...mppoly-off.png