CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[snappyHexMesh] Speeding up snappyHexMesh when using many regions

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   June 28, 2019, 13:05
Default Speeding up snappyHexMesh when using many regions
Senior Member
Join Date: Jul 2013
Posts: 123
Rep Power: 11
wildfire230 is on a distinguished road
Hi All,

I am currently working with snappyHexMesh to create a flow geometry through a packed pebble bed with several thousands of spherical pebbles (I need to resolve the flow through the bed to account for heat transfer, etc...).

I have two options for working with snappyHexMesh. One option is to use surface mesh STL files for the pebbles, but these end up being 5-10 GB and present some memory limitations for my specific problem (running in parallel actually loads the full surface mesh on every processor, overflowing memory). It also adds another step of complexity, because if I rearrange my packed bed of pebbles, I have to regenerate surface mesh files, format them for snappyHexMesh, etc...

The other option is to simply make a list of regions using searchableSpheres with the known list of pebble centers. This results in a really simplified workflow for me, and I avoid any possible quality issues with the surface meshes that I've run into with the other option. However, it seems like adding several thousands of searchableSphere regions causes a significant slowdown in snappyHexMesh's performance. I'm actually very surprised by how significant this slowdown is. Even just generating the patches for a few thousand searchableSphere regions takes 100s to 1000s of seconds, and then each step of snappy is also significantly slower than when using the surface mesh option.

I would really prefer to use the searchableSpheres option because of the simplified workflow and avoiding surface mesh quality issues, but the slowdown is very severe. Ultimately I would actually like all of the pebbles to be in a single cellZone. Is there any way to speed up this process? Is it possible to put multiple searchableSpheres into a single region? Is there any possible way to speed up this process?

Currently my geometry and refinementSurfaces entries look like this:

 sphere0 {
    type searchableSphere;
    centre (0.2446325 0.163559 6.296035);
    radius 0.025;
 sphere0 {
    level (0 0);
    faceZone sphere0;
    cellZone sphereZone;
    cellZoneInside inside;
    faceType baffle;
wildfire230 is offline   Reply With Quote

Old   March 31, 2022, 04:38
Default Packed bed meshing using snappyHexMesh
New Member
Pratyush Kumar
Join Date: Jun 2019
Location: Mumbai
Posts: 19
Rep Power: 5
PRATBHARAT is on a distinguished road
Dear wildfire230,
Did you find the solution?
Also, how did you manage to create the multiple particles using the centre location of the particles?
I have the similar problem. I generated the packed bed using DEM simulation, now I am trying to create bed with position.

Thanks in advance !!
PRATBHARAT is offline   Reply With Quote


multi-region, scalability, searchablesphere, snappyhexmesh

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
[snappyHexMesh] Creating STL files with regions for snappyHexMesh nusivares OpenFOAM Meshing & Mesh Conversion 4 August 7, 2018 21:09
Mesh refinement regions with snappyHexMesh andrei.cimpoeru OpenFOAM Pre-Processing 4 January 25, 2016 08:58
[snappyHexMesh] Using snappyHexMesh for multiple enclosed regions richard_vega OpenFOAM Meshing & Mesh Conversion 0 November 13, 2014 15:28
[snappyHexMesh] SnappyHexMesh and MultiRegion - get regions from Salome to OF dzi OpenFOAM Meshing & Mesh Conversion 2 September 4, 2014 11:04
[snappyHexMesh] does SnappyHexMesh allows intersection of refinement regions douglasx OpenFOAM Meshing & Mesh Conversion 2 April 2, 2014 10:30

All times are GMT -4. The time now is 18:17.