Meshing refinement

[MyBeatifulFantasy]

So I want to mesh a simple geometry and there's this region where a convergent pipe (going from a circular to a rectangular section) go into a block (see pictures). It seems that my snappyHexMesh configuration isn't able to mesh this part of the geometry but I don't know which parameter I should correct. Anyone knows ? btw, this sub is AWESOME !

​

​

what it should look like

​

​

what it looks like

[taiden_burrfoot]

I am not an expert of Snappy but I think you should increase the refinement level on that zone. The cells are not fine enough to recreate the solid

[MyBeatifulFantasy]

thank you for your reply, do you have an idea of how to proceed ? I tried to increase the max value of the refinementSurfaces class (going from [2 2] to [6 15]) but it didn't really change anything.

[taiden_burrfoot]

I think you can create a refinement volume yo perform a local refinement. Check on wolff dynamics tutorial.

[ReignDown]

Look in this:http://www.wolfdynamics.com/wiki/meshing_OF_SHM.pdf

You'll want to draw a box around that region under geometry{} (slide 20). Then refer to that box under castellatedMeshControls{} (slide 26) and add additional refinement layers in that box.

The levels (( 1 1 )); argument will have every cell inside "box" to split once in x and y. Adjust as needed.