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-   -   Divergence while using RSM turbulence model (http://www.cfd-online.com/Forums/fluent/103186-divergence-while-using-rsm-turbulence-model.html)

Bharatt June 13, 2012 03:35

Divergence while using RSM turbulence model
 
Hello everyone,

i am running a simulation for different turbulence models for an airfoil. I am facing AMG divergence or sometimes FLOATING ERROR: OVERFLOW when i am shifting to RSM turbulence model.
the procedure i am following is achieving convergence in K-epsilon at first place and then shifting to RSM, the following parameters i used in initial(K-epsilon) stage.

Solver:- pressure based, Green-gauss node based
Viscous:- Standard K-epsilon
Boundary conditions(under turbulence):- K and epsilon
Scheme:- SIMPLE 1st order for 100 iterations then 2nd order(URF:- momentum reduced to 0.5 from 2nd order)

By about 4000 iterations convergence is achieved.
NOW, i go back to viscous:-
under solver-->viscous:- RSM, linear pressure strain etc and rest kept the same(parameters which i used for k-epsilon).

By about 100 iterations AMG divergence occurred

P.S:- please correct me if i am doing anything wrong!
-do i have to initialize it again?

thanks in advance :)

bharat


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