Convergence issue with continuity

Shamoon Jamshed · December 10, 2020, 11:52

Hello enthusiasts,

I am solving a sort of coupled problem using far-field and internal flow simulation through a nozzle. The far-field is at ground conditions and nozzle flow is at very high pressure. I used coupled base solver, the simulation is going fine with all the turbulence models and energy well below 1e-05 but continuity is with 1e-01 in residuals and not in a mood to come down. The mesh size is nearly 7 million. Can anyone suggest whats the problem?

Regards,

Shamoon Jamshed, Ph.D.

duri · December 11, 2020, 07:40

May be plot the continuity residual and check where the error is high. Fix could be different when error is high at jet entertainment region or when it is high on the jet.

LoGaL · December 11, 2020, 07:52

Can you detail a bit about the numbers and the model? Pictures of the domain ecc? What boundary conditions are you giving?

December 10, 2020, 11:52	Convergence issue with continuity	#1
Shamoon Jamshed Senior Member Shamoon Jamshed Join Date: Apr 2009 Location: Karachi Posts: 377 Rep Power: 18	Hello enthusiasts, I am solving a sort of coupled problem using far-field and internal flow simulation through a nozzle. The far-field is at ground conditions and nozzle flow is at very high pressure. I used coupled base solver, the simulation is going fine with all the turbulence models and energy well below 1e-05 but continuity is with 1e-01 in residuals and not in a mood to come down. The mesh size is nearly 7 million. Can anyone suggest whats the problem? Regards, Shamoon Jamshed, Ph.D.

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December 11, 2020, 07:40		#2
duri Senior Member duri Join Date: May 2010 Posts: 245 Rep Power: 16	May be plot the continuity residual and check where the error is high. Fix could be different when error is high at jet entertainment region or when it is high on the jet.

December 11, 2020, 07:52		#3
LoGaL Senior Member Lorenzo Galieti Join Date: Mar 2018 Posts: 373 Rep Power: 12	Can you detail a bit about the numbers and the model? Pictures of the domain ecc? What boundary conditions are you giving?