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

Low Mach number free-air condition

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 31, 2005, 03:03
Default Low Mach number free-air condition
  #1
Riaan
Guest
 
Posts: n/a
Hi guys,

I am running an airfoil at Low Mach numbers (M<0.05) in a "free-air" condition and having problems with steady state convergence.

The Boundary conditions are Pressure Far Field (and hence the Mach specification).I think maybe the solver has problems solving the compressible flow equations at such low Mach numbers -but because I am using pressure far-field, I must use Ideal gas i.e. compressible formulation.

Funny thing is, unsteady solver (2nd order implicit) seems to converge nicely.

Any advice?

  Reply With Quote

Old   March 31, 2005, 11:15
Default Re: Low Mach number free-air condition
  #2
dp
Guest
 
Posts: n/a
try the segregated solver
  Reply With Quote

Old   March 31, 2005, 13:43
Default Re: Low Mach number free-air condition
  #3
Riaan
Guest
 
Posts: n/a
Always been using Segregated.
  Reply With Quote

Old   March 31, 2005, 17:19
Default Re: Low Mach number free-air condition
  #4
Farid
Guest
 
Posts: n/a
Hi,

I think that as long as inside Fluent there is no low Mach preconditionning, and the solver is a usual Riemann solver, Fluent is unable to compute correctly low Mach flows.

It's a fact!!

Farid.
  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
How obtain a Mach number value from a case run with Xifoam solver?? lfgmarc OpenFOAM Programming & Development 0 June 15, 2011 03:00
pre-conditioning for low mach number compressible flow solver Shenren_CN Main CFD Forum 0 April 29, 2011 21:07
Boundary Conditions and solver for low Mach laminar air jet fbisetti OpenFOAM Running, Solving & CFD 1 September 13, 2006 12:49
non-dimensional analysis in Fluent Endee FLUENT 8 September 7, 2005 16:16
TVD scheme at low Mach number Axel Rohde Main CFD Forum 5 August 6, 1999 02:01


All times are GMT -4. The time now is 23:39.