CFD Online Logo CFD Online URL
Home > Forums > CFX

jet, diffusion

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

LinkBack Thread Tools Display Modes
Old   March 23, 2006, 09:41
Default jet, diffusion
Peter Svendsen
Posts: n/a
Hi, I'm a student and new to CFX. I'm trying to model a simple paralle jet (injecting CH4) in a fully turbulent moving stream of air. I'm using the "k-epsilon" model combined with the "homogeneous multiphase flow model (interphase transfer model= none)". The velocityprofile downstream looks nicely bell-shaped as it should, but the concentration-profile does'nt seem to develop, as if only molecular diffusion takes place. The expansion of the half-radius of the concentration downstream, is way below the expansion of the half-radius of the velocity-profile downstream ...

Is it wrong to use the homogeneous model? What model should I use instead?

Sincerely - Peter N. S.

  Reply With Quote

Old   March 23, 2006, 12:37
Default Re: jet, diffusion
Posts: n/a
Sounds to me as though your solution hasn't had time to converge fully (although I could well be wrong). Are you running steady or transient? How many time steps did you give it. Make sure your convergence target is nice and low Res < 1e-5. You also might want to loosen the under-relaxation on your species.
  Reply With Quote

Old   March 24, 2006, 16:42
Default Re: jet, diffusion
Posts: n/a
If you have CH4 and air, then this is a multicomponent simulation, not a multiphase simulation. Multiphase means that the 'fluids' (which might be fluids or solids) do not mix at the molecular level...
  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
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
2D Plane Jet Fluent Solution doug Main CFD Forum 10 October 16, 2013 00:47
Jet diffusion flame problem skarnani Phoenics 0 April 30, 2010 18:32
About the laminar jet diffusion flame length Sheng Chen Main CFD Forum 1 July 10, 2004 01:07
IMPINGING JET ........... HELP!!!!!!!! Amir Omoumi Main CFD Forum 10 August 30, 1999 22:11

All times are GMT -4. The time now is 01:15.