[blockMesh] Creating a geometry using Blockmesh

ulugbey · February 25, 2021, 16:03

Hi,

I need to create a geometry using the blockMesh. But I don`t have too much idea how to create this geometry using blockMesh. How many blocks should I generate?
I add the geometry. Could you give me an idea about that? I appreciate your helps.

simrego · February 26, 2021, 05:41

Hi

You can do it with 4 blocks and use arc for the edges.
But it seems like you could just create an axisymmetric domain.

ulugbey · February 26, 2021, 07:56

Is there a difference if I do it with 8 blocks?

simrego · February 26, 2021, 08:18

You can do it from at least 3 blocks. As I remember with 2 blocks you can't do it. It'll throw an error.
But with 3 blocks you will have ugly vertex coordinates, but with 4 blocks you will have the least blocks with "nice" vertex coordinates.
I shouldn't do it with more blocks since you will just make more useless work for yourself.
Or you can even create a quarter section and use symmetry patches. Then you will have one block.

So no, there won't be any difference if you divide it into 8 sections and create 8 blocks. But you won't have a "better" mesh, just more vertices, more blocks, more patches("block sides") -> more error sources...

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
[Gmsh] Creating 2 baffles in geometry	caja94	OpenFOAM Meshing & Mesh Conversion	1	October 7, 2018 05:05
[blockMesh] blockMesh error - Negative Volume Block	adoledin	OpenFOAM Meshing & Mesh Conversion	2	June 22, 2016 11:44
[ICEM] Creating mesh for fluid - solid geometry	tmu	ANSYS Meshing & Geometry	1	March 5, 2016 07:14
Problem with building geometry - concentric cylinders	Rhoddwen	OpenFOAM Pre-Processing	9	December 17, 2014 11:02
Possible Bug in pimpleFoam (or createPatch) (or fluent3DMeshToFoam)	cfdonline2mohsen	OpenFOAM	3	October 21, 2013 10:28

February 26, 2021, 05:41		#2
simrego Senior Member anonymous Join Date: Jan 2016 Posts: 416 Rep Power: 14	Hi You can do it with 4 blocks and use arc for the edges. But it seems like you could just create an axisymmetric domain.

February 26, 2021, 07:56		#3
ulugbey Member Join Date: Dec 2020 Posts: 38 Rep Power: 5	Is there a difference if I do it with 8 blocks?

February 26, 2021, 08:18		#4
simrego Senior Member anonymous Join Date: Jan 2016 Posts: 416 Rep Power: 14	You can do it from at least 3 blocks. As I remember with 2 blocks you can't do it. It'll throw an error. But with 3 blocks you will have ugly vertex coordinates, but with 4 blocks you will have the least blocks with "nice" vertex coordinates. I shouldn't do it with more blocks since you will just make more useless work for yourself. Or you can even create a quarter section and use symmetry patches. Then you will have one block. So no, there won't be any difference if you divide it into 8 sections and create 8 blocks. But you won't have a "better" mesh, just more vertices, more blocks, more patches("block sides") -> more error sources...