[subhasis]

Hi ,

I am running snappyHexMesh in cluster by using the following command
mpirun --np 10 snappyHexMesh

in some scenario the snappyHexFails (This is a normal use case)
when snappyHexmesh fails the in some cases the control does not come out gracefully , it hangs in the terminal .
In case of snappyHex Mesh success the control comes out properly .
Can any one help me on this

Thanks
B.

[Taataa]

When you want to run it in parallel you should add -parallel flag, also you may add -overwrite flag as well so it doesn't create a mesh in a new time step. So it should be:

mpirun --np 10 snappyHexMesh -parallel -overwrite

I always use foamJob for running cases to make it easier. The equivalent of this command with foamJob is:

foamJob -w -a -p snappyHexMesh -overwrite >&/dev/null

-w: wait for execution to complete
-a: append to log file instead of overwriting it
-p: parallel run of processors

[subhasis]

Hi
Thank you for reply
When i try to use foamJob -parallel snappyHexMesh , it gives me a eerror like

Case is not currently decomposed
system/decomposeParDict exists
Try decomposing with foamJob decomposePar""


Thanks
B.

[Antimony]

Hi,

If you want to run anything in parallel, the case must first be split/ decomposed based on the number of processors you want to run the parallel application on.

So before you run snappyHexMesh in parallel with 10 processors, you need to have decomposed the case such that there are 10 processor folders, each of which contains a region that will be acted on by one processor. This is typically done after running blockMesh and creating the original mesh.

In order to perform this splitting, you need to run decomposePar. And once your have the processor* directories, you can run snappyHexMesh or any other application in parallel.

Hope this helps.

Cheers,
Antimony

[Taataa]

Here are the steps that you need to perform for running snappyHexMesh in parallel:

# Clean the case
foamJob -w -a foamCleanTutorials >&/dev/null

# Generate background mesh
foamJob -w -a blockMesh >&/dev/null

# Extracts  surface features 
foamJob -w -a surfaceFeatureExtract >&/dev/null

# Domain decomposition
foamJob -w -a decomposePar >&/dev/null

# Generate 3D mesh
foamJob -w -a -p snappyHexMesh -overwrite >&/dev/null

# Reconstruct the generated mesh in constant directory
foamJob -w -a reconstructParMesh -constant >&/dev/null

# Check mesh quality, look for non-orthogonality and skewness
foamJob -w -a checkMesh >&/dev/null

You can put all these commands in a bash file, say meshing.sh, then run the bash file. Don't forget that you need to have a decomseParDict file in your system directory.