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

Moving cone tutorial runs with velocity motion solver but fails with displacement

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

LinkBack Thread Tools Search this Thread Display Modes
Old   October 31, 2021, 08:28
Default Moving cone tutorial runs with velocity motion solver but fails with displacement
Join Date: Sep 2018
Posts: 53
Rep Power: 7
tecmul is on a distinguished road
Hi all,
I'm working on fluid-structure interaction with pimpleFoam and I've run into a problem with adaptive time stepping; the time step oscillates very rapidly. This oscillation is caused by oscillation in the Courant number, which is itself caused by oscillation in the mesh. I use the displacementSBRStress mesh motion solver together with the rigidBodyDynamics library in OpenFOAM v2006, but the problem also occurs with displacementLaplacian.

I simplified the problem by ditching FSI and testing forced boundary motion on the same mesh. The problem is still present when solving with displacementLaplacian, but is completely resolved when using the velocityLaplacian solver. I'd use velocityLaplacian for my FSI case as well, but the rigidBodyDynamics library only works with displacement mesh motion solvers.

I figured that maybe something about my case's settings or mesh might be causing the issue, so I moved to testing simple tutorial cases. The moving cone tutorial of pimpleFoam uses the velocityComponentLaplacian mesh motion solver and it runs fine. I changed the tutorial to use displacementComponentLaplacian, and at about t = 0.002 the same issue of mesh oscillation pops up! The mesh starts oscillating back and forth and quickly fails. I've attached the files for this case.

Does anyone have ideas as to what might be causing this? The equation being solved is the same Laplace equation, only the field being solved for is different, so why is the displacement mesh solver so unstable? I've tried different Laplacian schemes, time steps and looping over the Laplace equation multiple times, nothing helped.
Attached Files
File Type: zip (98.1 KB, 19 views)
tecmul is offline   Reply With Quote


displacement solver, displacementlaplacian, oscillation, velocity solver, velocitylaplacian

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 remove blockmesh geometry philipp1 OpenFOAM Running, Solving & CFD 2 December 12, 2014 10:58
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
Working directory via command line Luiz CFX 4 March 6, 2011 20:02
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 15:45
Variables Definition in CFX Solver 5.6 R P CFX 2 October 26, 2004 02:13

All times are GMT -4. The time now is 15:19.