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

QUESTIONS about Coupled Implicit

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 6, 2005, 22:05
Default QUESTIONS about Coupled Implicit
  #1
manish
Guest
 
Posts: n/a
Hi Everyone,

I just had some general questions about the coupled implicit solver:

1. Is it okay if your final run has a second order flow, but a first order turbulence model? (Once I turn on the second order upwind for the standard k-e...a lot of weird stuff happens....ie. turbulent viscosity goes very high, then temperature and pressure goes too high, residuals start diverging and levels out constantly, eventually whenever there is adaption, the solution diverges and kills itself. )

2. i am running a cold nitrogen gas flow through a supersonic nozzle and I want to see the pressure impingements on a flat plate. I get really good convergence when i run a second order flow but a first order turbulence model. is this okay??

3. when should i turn on the second order turbulence model? Can i turn it on after the mass imbalance is close to zero?

4. What equation should i use to determine the turbulent viscosity ratio? I know that it is laminar viscosity/turbulent viscosity.

5. i got really high turbulent viscosity ratio cells, but i do not know how to get rid of them. is it because my elements are too skewed?

hope to hear from you soon. thank you. regards, manish
  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
DPM Coupled Implicit Aimara FLUENT 0 April 25, 2007 16:23
Multigrid and Coupled Solver oevermann OpenFOAM Running, Solving & CFD 2 October 29, 2005 12:32
Convergence with coupled implicit solver Henrik Ström FLUENT 1 October 29, 2005 03:57
Any questions about implicit Runge-Kutta methods? Runge_Kutta Main CFD Forum 3 March 4, 2005 18:36
Help! Coupled Vs Implicit - Total temperature sile FLUENT 3 March 10, 2003 16:58


All times are GMT -4. The time now is 01:51.