CFD Online Logo CFD Online URL
Home > Forums > CFX

calculate time scale for mesh deformation analysis

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

LinkBack Thread Tools Display Modes
Old   October 23, 2009, 05:54
Default calculate time scale for mesh deformation analysis
New Member
Join Date: Oct 2009
Posts: 1
Rep Power: 0
wilsonbrad is on a distinguished road
Sponsored Links
Am performing pressure relief valve analysis, the problem setup is similar to tutorial 21.I did not find any difficulty while perform tutorial 21.Though I use same boundary condition for my case,after two iterations getting overflow error .. The geometry have clearance between piston and outer surface of the valve is 0.039mm (39 micron gap).
  • I preferred same time scale which is used in tutorial 21. Am not confident about set the time scale for mesh motion analysis.
  • Generated the unstructured hexa mesh for entire geometry.
can anyone help me to resolve it
wilsonbrad is offline   Reply With Quote
Sponsored Links

Old   October 23, 2009, 06:44
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 13,721
Rep Power: 106
ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
Overflow errors usually mean the solver has diverged. This could be due to poor mesh quality, unphysical boundary conditions or poor numerics. To address these issues:
1) Check the mesh quality when it is diverging. If the quality is poor you will need to revise your meshing.
2) Check that the boundary conditions you have are correct. Does it converge if you use a stationary mesh? It will need to converge with a stationary mesh before it will work with a moving mesh.
3) Use a smaller time step or ramp the pressure up to the full pressure over a period of time. Also check your convergence tolerance is OK.
ghorrocks is offline   Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Time Scale in Fluent Andrew FLUENT 0 April 20, 2009 01:24
Computational time sunnysun OpenFOAM Running, Solving & CFD 5 March 16, 2009 04:32
Differences between serial and parallel runs carsten OpenFOAM Bugs 11 September 12, 2008 11:16
Modeling in micron scale using icoFoam m9819348 OpenFOAM Running, Solving & CFD 7 October 27, 2007 00:36
time averaged heat transfer in oscillating flow Matthieu Ubas Main CFD Forum 2 November 5, 1999 15:20

Sponsored Links

All times are GMT -4. The time now is 22:01.