[Tesseractic]

From my reading I have decided that I want a hexahedral mesh, so SnappyHexMesh would seem to be desirable, except that SnappyHexMesh seems to require that one first run BlockMesh, which requires a BlockMeshDict file containing a description of the geometry to be meshed.

My problem is this: how do I get from Solidworks model to BlockMeshDict?

To complicate matters somewhat, I am not the one running Solidworks; that's someone else in the same city.


Thanks in advance, Graham.

[jherb]

Your blockmesh can be a cube with just one cell (or 8) which is larger than you final flow domain. SnappyHexMesh will use this as starting mesh but will do all the refinements necessary and cut out all space outside the boundaries.

(see all the tutorials, e.g. motorbike, which use snappyHexMesh)

[kera]

Originally Posted by Tesseractic

From my reading I have decided that I want a hexahedral mesh, so SnappyHexMesh would seem to be desirable, except that SnappyHexMesh seems to require that one first run BlockMesh, which requires a BlockMeshDict file containing a description of the geometry to be meshed.

My problem is this: how do I get from Solidworks model to BlockMeshDict?

To complicate matters somewhat, I am not the one running Solidworks; that's someone else in the same city.


Thanks in advance, Graham.

Hey,

These are the steps I usually follow to bring a geometry in the OpenFOAM environment for meshing:

Step 1: Save your Geometry in IGS/STP format.
Step 2: Import the geometry in a thrid party software where you can organize your components for say, Inlet, outlet, walls etc... and save it in STL format
Step 3: Place the STL file in your constant/triMesh
Step 4: In order to use snappyHexMesh you need a base mesh, which is usually a block incorporating your whole geometry.
Step 5: Choose a random point (x,y,z) within your geometry as this is one of the parameter required by the snappyHexMeshDict, to say which mesh to keep.

From here you can follow an excellent youTube tutorial whereall the steps are explained in detail, here is the link.

some more tutorials for snappyHexMesh can be easily found in the tutorials folder as Joachim mentioned.

in the command prompt after sourcing the OpenFoam version hit the following commands.

tut 

grep -r "snappyHexMesh" .

hope this helps!

Regards,
Ricky

[Tesseractic]

Originally Posted by jherb

Your blockmesh can be a cube with just one cell (or 8) which is larger than you final flow domain. SnappyHexMesh will use this as starting mesh but will do all the refinements necessary and cut out all space outside the boundaries.

(see all the tutorials, e.g. motorbike, which use snappyHexMesh)

Actually, the problem involves a pipe (actually a cyclone) with 2 output ends plus another pipe branching off the middle for an inlet, so I don't think this particular piece of advice will be helpful. Somehow I have to get into BlockMeshDict format the geometry that is currently (after being output from Solidworks) in STL format. The point is that BlockMeshDict seems to require a representation of the model, but nothing seems to write a BlockMeshDict file.

How do I create a BlockMeshDict from the STL file, or any other format that Solidworks can output?


Regards, Graham.

[Tesseractic]

Originally Posted by kera

Hey,

These are the steps I usually follow to bring a geometry in the OpenFOAM environment for meshing:

Step 1: Save your Geometry in IGS/STP format.
Step 2: Import the geometry in a thrid party software where you can organize your components for say, Inlet, outlet, walls etc... and save it in STL format
Step 3: Place the STL file in your constant/triMesh
Step 4: In order to use snappyHexMesh you need a base mesh, which is usually a block incorporating your whole geometry.
Step 5: Choose a random point (x,y,z) within your geometry as this is one of the parameter required by the snappyHexMeshDict, to say which mesh to keep.

From here you can follow an excellent youTube tutorial whereall the steps are explained in detail, here is the link.

some more tutorials for snappyHexMesh can be easily found in the tutorials folder as Joachim mentioned.

in the command prompt after sourcing the OpenFoam version hit the following commands.

tut 

grep -r "snappyHexMesh" .

hope this helps!

Regards,
Ricky

Thanks Ricky, I followed most of that. I have a problem with step 2, though. Which 3rd party tools can be used here and how does one actually specify the walls, inlets and outlets?

Regards, Graham.

[kera]

Originally Posted by Tesseractic

Thanks Ricky, I followed most of that. I have a problem with step 2, though. Which 3rd party tools can be used here and how does one actually specify the walls, inlets and outlets?

Regards, Graham.

you can use SALOME for that, a good tutorial is given by Tobias Holzmann, which you can find here.

Regards,
Ricky