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

urgent help needed with 2d compressible flow

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 19, 2007, 13:14
Default urgent help needed with 2d compressible flow
  #1
James
Guest
 
Posts: n/a
Hello everyone,

I am simulating a 2d compressible flow of methane/air and i am having problems....i do the cold flow first incompressible and then change to compressible and it works fine and residuals are behaving fine. When i switch to the hot flow using the species transport and the eddy dissipation/finite rate chemistry model, my flame is not good and i also get my velocity field completely reversed and my flame eventually begins to propagate in the flame holder. My residuals are also fluctuating meanwhile my flow is steady.

I tried the same case hot but incompressible ideal gas and it works fine. I also have a 3d case and it works fine with the compressible flow as well.

So my question is why is the compressible 2d hot case not working? Is it due to the pressure at the outlet.....in the 3d case, one has the option is setting radial equilibrium pressure distribution at the outlet but i do not see this option in the 2d case?

If you have any way around this problem, i will be grateful for yor input.

James

  Reply With Quote

Old   June 19, 2007, 23:15
Default Re: urgent help needed with 2d compressible flow
  #2
thandavan
Guest
 
Posts: n/a
Hi,

Good initial guess will solve your problem. For example you can use the fluent manual to calculate the k and epsilon values and also initializing the velocity field will help over come this issue.

Thandavan
  Reply With Quote

Old   June 20, 2007, 04:22
Default Re: urgent help needed with 2d compressible flow
  #3
James
Guest
 
Posts: n/a
Hi,

Thanks for responding to my post. I realized that i had done the wrong specification for the velocity field. When i changed that, i worked fine.

James

  Reply With Quote

Reply

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
About compressible flow at low mach hit Main CFD Forum 2 October 26, 2009 21:21
Compressible Fluid Flow in COMSOL Multiphysics BBG COMSOL 1 November 19, 2008 14:05
URGENT ! Need help on Axisymmetric Flow ! Suman Kumar Main CFD Forum 1 November 20, 2001 14:51
Solving unsteady compressible low speed flow atit Main CFD Forum 8 July 31, 2000 13:19
compressible channel flow.. R.D.Prabhu Main CFD Forum 0 July 17, 1998 17:23


All times are GMT -4. The time now is 05:32.