CFD Online Logo CFD Online URL
Home > Forums > FLUENT

pressure correction or mesh quality

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

LinkBack Thread Tools Display Modes
Old   February 7, 2013, 07:47
Default pressure correction or mesh quality
New Member
Join Date: Nov 2012
Posts: 7
Rep Power: 5
michel2008 is on a distinguished road
Dear all,

I am trying to simulate laminar flow in micro-cylinders embedded in a rectangular microchannel so I simplified the model with a unit cell which is a square microchannel including a micro-cylinder with an inlet and outlet by apply periodic boundary condition in the inlet and outlet (I used mass-flow rate for inlet boundary condition).
The point is when I applied periodic boundary condition in Fluent, an error just appeared before the first iteration calculating solution "divergence detected in AMG solver-pressure correction" . Although I tried to overcome this problem by reducing under relaxation factor and change some parameters in solution control, unfortunately I could not be able to solve it.
In the other hand when I want to make periodic region in inlet and outlet in mesh utility, but the coordinate system light yellow prevent to well define it.

I suggest maybe it is related to mesh quality and i have to make a finer mesh, do you have any suggestion about the mesh or solving this problem.
Any help would be greatly appreciated.

michel2008 is offline   Reply With Quote

Old   February 7, 2013, 08:28
Join Date: Dec 2012
Location: Calgary, Alberta, Canada
Posts: 39
Rep Power: 4
mrenergy is on a distinguished road
Hi michel

I think it is not mesh quality related problem ... the convergence happens before the solution at all ...

It seems to be a problem in the boundary conditions ...
review ALL your boundary conditions CAREFULLY, and check that is physically consistent and acceptable.


mrenergy is offline   Reply With Quote

Old   February 7, 2013, 11:57
New Member
Join Date: Nov 2012
Posts: 7
Rep Power: 5
michel2008 is on a distinguished road
Dear Mamdouh

Thanks for your reply.

I have checked and it seems there is not anything wrong in boundary condition. But when I tried to change to a finer mesh, the solution give me the same error after 2 iteration. Do you think this problem would be solved with a special mesh or you have any idea about it?

michel2008 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
[ICEM] Negative volume error in hybrid mesh siw ANSYS Meshing & Geometry 4 September 3, 2014 05:25
how to set periodic boundary conditions Ganesh FLUENT 13 January 22, 2014 05:11
Layers:problem with curvature giulio.topazio OpenFOAM Native Meshers: snappyHexMesh and Others 10 August 22, 2012 09:03
increasing mesh quality is leading to poor convergence tippo CFX 2 May 5, 2009 10:55
changing the coefficients of pressure correction Noel Phoenics 1 April 7, 2009 08:54

All times are GMT -4. The time now is 19:08.