|February 7, 2012, 07:29||
Solution not converging, but oscillating residuals around a constant value
Join Date: Feb 2012
Posts: 1Rep Power: 0
Hi Fluent users,
I am a new fluent user and I am analysing an impingement system for a vane internal cooling passage, using a realizable k-eps model.
I started using a incompressible ideal gas, the solution converged without any problems but the calculated density was completely wrong, so I changed the material as an ideal gas. Now my solution doesn't converge anymore: all the residuals oscillate around a constant value, and in particular the continuity residuals oscillate around a value which is far from the convergence criteria one.
I tried to change the under relaxation factors (it dumps the oscillatins but it doesn't improve the convergence), to use a finer mesh and to use the fluent mesh adaptation tool but without any results.
Can anbody help me?
|February 7, 2012, 12:21||
Join Date: Feb 2011
Posts: 6Rep Power: 7
It is difficult to judge from the few information you gave
What is the pressure and velocity value at the injection system (or maximum pressure in the system) ? Do you have good values of y+ ? Did you check the quality of your mesh ?
Below are a few things you could try :
- Using the density based solver
- start with a lower mass flow (or velocity or pressure) inlet and increase it gradually
- Start by an inviscid flow then add turbulence
|convergence issues, oscillating residuals|
|Thread||Thread Starter||Forum||Replies||Last Post|
|Convergence||Centurion2011||FLUENT||27||February 7, 2016 12:58|
|grid dependancy||gueynard a.||Main CFD Forum||19||June 27, 2014 21:22|
|Accuracy and convergence||pawan1989||FLUENT||5||April 15, 2010 17:17|
|CFL Condition||Matt Umbel||Main CFD Forum||14||January 12, 2001 15:34|
|Wall functions||Abhijit Tilak||Main CFD Forum||6||February 5, 1999 02:16|