CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Domain decomposition of 3D overset grid case

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

LinkBack Thread Tools Search this Thread Display Modes
Old   December 21, 2017, 14:12
Default Domain decomposition of 3D overset grid case
New Member
Owen Jones
Join Date: Aug 2017
Location: Martinique
Posts: 2
Rep Power: 0
tok3rat0r is on a distinguished road
I'm currently working on a 3D overset-grid hydrodynamic simulation with overInterDyMFoam from OpenFOAM v1706. I have the mesh set up, and the simulation runs, but I'm having problems figuring out a 'recipe' for parallel decomposition.

Each time I try a different decomposition method/number of processes, the stability and speed of the calculation seem to change pretty much at random. I've found a 12-processor hierarchical decomposition which runs reasonably well, but I'd really like to use more of the computational resources at my disposal (up to 64 cores per node with 2 nodes available)!. I tried a Scotch decomposition into 24 processes, which also seemed to start running well enough, but the overset analysis/mesh.update() stage took a painfully long time (well over 200 s, as opposed to 93 s with the 12-process hierarchical decomposition). A 16-process hierarchical decomposition was catastrophically unstable, and various other combinations have either been too unstable or run too slowly.

Are there any rules of thumb for effective decomposition of overset cases?
tok3rat0r is offline   Reply With Quote

Old   December 29, 2017, 06:05
Senior Member
Join Date: Apr 2012
Location: France
Posts: 1,110
Rep Power: 26
Yann will become famous soon enough
Have you tried a scotch decomposition on 12 processors?

You can't compare a 12 processors hierarchical decomposition with a 24 proc scotch one because you have no idea if the speedup/slowdown is due to the decomposition method or something related to your hardware.
Yann is offline   Reply With Quote

Old   February 24, 2023, 02:58
New Member
Join Date: Feb 2022
Posts: 4
Rep Power: 4
Hussamsababha is on a distinguished road
Scotch is often not recommended in overset mesh. I'd recommend heirechal
Hussamsababha is offline   Reply With Quote


decomposepar, multiphase flow, overset mesh, parallel calculation

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
decomposition of multi domain cases for large simulations romant OpenFOAM Pre-Processing 6 May 10, 2023 21:27
potential flows, helmholtz decomposition and other stuffs pigna Main CFD Forum 1 October 26, 2017 08:34
bubbleFoam - Simple case, Large bubble, closed domain darai OpenFOAM Running, Solving & CFD 9 October 12, 2015 05:40
injection problem Mark New FLUENT 0 August 4, 2013 01:30
how to get rid of skipping thread 5 of domain field-1 (not referenced by grid) smkhan FLUENT 0 November 16, 2009 04:20

All times are GMT -4. The time now is 07:07.