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

absolute pressure limit

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 24, 2007, 06:59
Default absolute pressure limit
  #1
Jianfeng Zou
Guest
 
Posts: n/a
Dear everyone. I run a 3D case with fluent. After 100+ iterations, the solver present 'absolute pressure limited to 1.0 in xx cells on zone xx'. Ideal gas was used. How should I do? Should I refine my grid system. If the computation continues, a resonable solution will be achieved finally?

  Reply With Quote

Old   October 24, 2007, 12:13
Default Re: absolute pressure limit
  #2
AJK
Guest
 
Posts: n/a
let the simulation run for a while and this error may go away or else you need to make ur mesh fine in that particular area or use grid adaption technique
  Reply With Quote

Old   October 24, 2007, 19:13
Default Re: absolute pressure limit
  #3
Venkatesh V
Guest
 
Posts: n/a
If you are running transient problem reduce the time step. If you are running steady state reduce the under relaxation factors.

I think currently your Min absolute pressure 1. I would suggest you set that to reasonable valve. I would suggest you to set resonable limits for all the values.

Thanks Venkatesh V
  Reply With Quote

Old   October 24, 2007, 21:02
Default Re: absolute pressure limit
  #4
Jianfeng Zou
Guest
 
Posts: n/a
Dear AJK and Venkatcsh V, I am simulating a turbulence diffusion hydrogen flame(the incoming air is supersonic and the fuel is sonic). I found the low pressure (about the pressure limit 1.0 Pa) locate mainly in the near region around the hydrogen jet. Besides mesh finement, using small time step size, etc, what else should I do to the boundary condition or initial condition?

Bye the way, after 100+ iterations with pressure limit warning, my calculation seem to be steady, anyway.
  Reply With Quote

Old   October 25, 2007, 02:56
Default Re: absolute pressure limit
  #5
goldenland
Guest
 
Posts: n/a
When I simulate the supersonic gas flow in the nozzle, I met the same problem. In this case, I change the limitation value of the absolute pressure(solve->control->limits...->absolute pressure) to a very small value.

In my case, the problem is solved. So you can try yours.

Good luck.
  Reply With Quote

Reply

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
Fluent natural ventilation pressure boundary condition pierresandre FLUENT 24 November 8, 2011 14:32
Pressure BC for combustion chamber Giuki FLUENT 1 July 19, 2011 11:35
absolute pressure limited to 1.0 St├ęphane FLUENT 0 March 3, 2008 06:25
Neumann pressure BC and velocity field Antech Main CFD Forum 0 April 25, 2006 02:15
what the result is negatif pressure at inlet chong chee nan FLUENT 0 December 29, 2001 05:13


All times are GMT -4. The time now is 15:40.