[snappyHexMesh] How can I reduce RAM consumption of snappyHexMesh?

songyi719 · March 9, 2023, 02:29

I knew that 1M cells consume about 1~2gb of RAM, according to many others' post.

But currently my snappyhexmesh creates about 5~6gb load per 1M cells. I must be able to create 300% of current cell # by that rule, but my snappyhexmesh keeps crash due to RAM shortage

How can I reduce RAM consumption of mesh? Is there any factor that differs RAM consumption I can control?

rmaries · March 13, 2023, 04:54

Hi,

It also depends on the input .stl or .obj mesh size. If your input .stl contains lot of unwanted surfaces or it is very fine, that will take more memory.

Once I tried to create volume mesh for the car without cleaning the interior and only by filling the gaps of cabin. It fails due to memory overload. I used aws with 512 gb instance. I didn't try that to solve again.

When I try the same case with cleaned interior, it works fine

Best Regards
Maries

cibanez · March 20, 2023, 11:09

Hi,

As Maries suggest, your memory might be filling up due to large size of stl's for geometry surfaces. If you are meshing in parallel you could try type distributedTriSurfaceMesh; instead of type triSurfaceMesh; for your .stl or .obj surfaces.

Check this link:
https://www.openfoam.com/documentati...rfacemesh.html

March 9, 2023, 02:29	How can I reduce RAM consumption of snappyHexMesh?	#1
songyi719 Member Song Young Ik Join Date: Apr 2022 Location: South Korea Posts: 57 Rep Power: 4	I knew that 1M cells consume about 1~2gb of RAM, according to many others' post. But currently my snappyhexmesh creates about 5~6gb load per 1M cells. I must be able to create 300% of current cell # by that rule, but my snappyhexmesh keeps crash due to RAM shortage How can I reduce RAM consumption of mesh? Is there any factor that differs RAM consumption I can control?

March 20, 2023, 11:09		#3
cibanez New Member Cristóbal Join Date: Jan 2022 Location: Sweden Posts: 14 Rep Power: 4	Hi, As Maries suggest, your memory might be filling up due to large size of stl's for geometry surfaces. If you are meshing in parallel you could try type distributedTriSurfaceMesh; instead of type triSurfaceMesh; for your .stl or .obj surfaces. Check this link: https://www.openfoam.com/documentati...rfacemesh.html Yann, wht and songyi719 like this.

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March 13, 2023, 04:54		#2
rmaries Member Maries Join Date: Mar 2010 Location: Cologne, Germany Posts: 75 Rep Power: 16	Hi, It also depends on the input .stl or .obj mesh size. If your input .stl contains lot of unwanted surfaces or it is very fine, that will take more memory. Once I tried to create volume mesh for the car without cleaning the interior and only by filling the gaps of cabin. It fails due to memory overload. I used aws with 512 gb instance. I didn't try that to solve again. When I try the same case with cleaned interior, it works fine Best Regards Maries