divergence detected

arthur john · April 19, 2014, 05:14

i did my meshing in gambit(3d circular jet with a v notch at the nozzle exit ) but my case is diverging in fluent..esp divergence in amg solver temp,.By checking the case set up i found that skewness exceeded 0.98 at 1 cell on thread ID=5. how can i fix my issue ?

-mAx- · April 28, 2014, 01:40

you have bad quality cells which may cause divergence
I would fix skewness problem (go back in Gambit)

arthur john · April 28, 2014, 12:07

thanx max.But how can i fix skewness prob in gambit.Do i need to change the interval count or size or anything else ? am doing on v toch ( at exit ) and i am able to mesh only t grid at that volume.Does t grid has any influence on skewness or divergence ?

-mAx- · April 29, 2014, 02:59

you need to find the reason of your skewness
Typically it is linked to a topology issue (sharp angle etc...)

April 19, 2014, 05:14	divergence detected	#1
arthur john New Member arthur Join Date: Apr 2014 Posts: 9 Rep Power: 12	i did my meshing in gambit(3d circular jet with a v notch at the nozzle exit ) but my case is diverging in fluent..esp divergence in amg solver temp,.By checking the case set up i found that skewness exceeded 0.98 at 1 cell on thread ID=5. how can i fix my issue ?

April 28, 2014, 01:40		#2
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	you have bad quality cells which may cause divergence I would fix skewness problem (go back in Gambit) __________________ In memory of my friend Hervé: CFD engineer & freerider

April 29, 2014, 02:59		#4
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	you need to find the reason of your skewness Typically it is linked to a topology issue (sharp angle etc...) __________________ In memory of my friend Hervé: CFD engineer & freerider

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April 28, 2014, 12:07		#3
arthur john New Member arthur Join Date: Apr 2014 Posts: 9 Rep Power: 12	thanx max.But how can i fix skewness prob in gambit.Do i need to change the interval count or size or anything else ? am doing on v toch ( at exit ) and i am able to mesh only t grid at that volume.Does t grid has any influence on skewness or divergence ?