CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

under relaxation factors

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

LinkBack Thread Tools Display Modes
Old   November 29, 2011, 06:36
Default under relaxation factors
Join Date: Aug 2009
Posts: 67
Rep Power: 10
spk is on a distinguished road
Hi everyone,

I simulate a hydrofoil under non-cavitating conditions using Flunet.
The under-relaxation factors that i use are:
pressure 0.8
density 1
body forces 1
momentum 0.2
turbulent kinetic energy 0.8
turbulent dissipation rate 0.8
turbulent viscosity 1
Also i use Simple algorithm and k-ε standard

I want to converge Cl and Cd. After a great number of iterations Cd and Cl change value every ten iterations. If i change the under-relaxation factors
and define all of them with the value 0.01, i see that Cd and Cl dont change any more!
Is that right movement? I change under-relaxation factors and i have convergence?

spk is offline   Reply With Quote

Old   November 29, 2011, 06:57
Senior Member
Emre G
Join Date: May 2011
Location: Turkey
Posts: 123
Rep Power: 8
emreg is on a distinguished road
you have to use URF when your work cant be converged.
if your simulations isnt so complex that it has transient behaviour, u dont need to modify URF.
emreg is offline   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
Relaxation Factors for Transient solvers philippose OpenFOAM Running, Solving & CFD 19 March 20, 2014 05:39
Purpose of relaxation factors Mohsin FLUENT 5 April 30, 2010 11:57
relaxation factors and time accuracy Mike Main CFD Forum 7 May 21, 2005 12:41
Relaxation Factors Tim Phoenics 3 June 30, 2004 02:03
relaxation factors zhujianguo Phoenics 1 August 5, 2003 06:17

All times are GMT -4. The time now is 14:33.