CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM

pRefCell on Parallel Simuations

Register Blogs Community New Posts Updated Threads Search

Like Tree2Likes
  • 1 Post By Yahoo
  • 1 Post By cfdonline2mohsen

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 5, 2013, 15:53
Default pRefCell on Parallel Simuations
  #1
New Member
 
Join Date: Apr 2012
Posts: 21
Rep Power: 14
Yahoo is on a distinguished road
Hi
I have developed a solver which works fine on single processor, but diverges when I am running it on multiple processors. For the later, by changing the cell at which pressure is set (pRefCell), my results change. i.e. pRefCell is affecting the results on parallel simulations! Any hints?
ScarFace likes this.
Yahoo is offline   Reply With Quote

Old   June 10, 2013, 05:58
Default
  #2
Senior Member
 
cfdonline2mohsen's Avatar
 
Mohsen KiaMansouri
Join Date: Jan 2010
Location: CFD Lab
Posts: 118
Rep Power: 16
cfdonline2mohsen is on a distinguished road
Dear Yahoo
As you know pressure is a relative quantity in numerical calculations because it it 1st order (e.g. dpdx in Navier-Stokes Equation). in order to assign absolute values for pressure you Must fix the pressure at one point of your simulation that you know the pressure (for example you can fix the pressure at one point in outlet if it flows to atmosphere).
so it is evident that if you use different values for pRefCell, you will obtain different Absolute Pressure but the relative pressure between 2 points will be the same.

Best Regards
Kia
ScarFace likes this.
cfdonline2mohsen is offline   Reply With Quote

Reply


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
Can not run OpenFOAM in parallel in clusters, help! ripperjack OpenFOAM Running, Solving & CFD 5 May 6, 2014 15:25
parallel Grief: BoundaryFields ok in single CPU but NOT in Parallel JR22 OpenFOAM Running, Solving & CFD 2 April 19, 2013 16:49
Running in parallel Djub OpenFOAM Running, Solving & CFD 3 January 24, 2013 16:01
Script to Run Parallel Jobs in Rocks Cluster asaha OpenFOAM Running, Solving & CFD 12 July 4, 2012 22:51
Parallel Computing Classes at San Diego Supercomputer Center Jan. 20-22 Amitava Majumdar Main CFD Forum 0 January 5, 1999 12:00


All times are GMT -4. The time now is 01:16.