Flow equations convergence

AkhilHG · June 16, 2016, 06:16

I have a model with a helical twist of 10 turns inside a pipe and I'm trying to simulate the flow of water inside this pipe under uniform heat flux conditions.
But my flow equations in the residuals graph are not converging even at 10000 iterations.
My mesh orthogonal quality : 0.157
Aspect ratio : 36.78
Can anyone suggest ideas to solve this?

sarodesr · June 23, 2016, 07:29

Hi,

I am giving some general ideas or approach. hope this will help.
Decrease under relaxation parameters that will help in convergence. Check mass imbalance in the systems. It should not be more than 2-3 % of your inlet mass in system. First solve for flow variables then switch to energy equation. New version of fluent starts from second order discretization, change it to first order and then change it back to desired order. Try to feed relevant turbulence parameters than default one.

-Sarang

June 16, 2016, 06:16	Flow equations convergence	#1
AkhilHG New Member Akhil H G Join Date: Jun 2016 Location: India Posts: 1 Rep Power: 0	I have a model with a helical twist of 10 turns inside a pipe and I'm trying to simulate the flow of water inside this pipe under uniform heat flux conditions. But my flow equations in the residuals graph are not converging even at 10000 iterations. My mesh orthogonal quality : 0.157 Aspect ratio : 36.78 Can anyone suggest ideas to solve this?

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June 23, 2016, 07:29		#2
sarodesr New Member Sarang Join Date: Jul 2013 Posts: 13 Rep Power: 13	Hi, I am giving some general ideas or approach. hope this will help. Decrease under relaxation parameters that will help in convergence. Check mass imbalance in the systems. It should not be more than 2-3 % of your inlet mass in system. First solve for flow variables then switch to energy equation. New version of fluent starts from second order discretization, change it to first order and then change it back to desired order. Try to feed relevant turbulence parameters than default one. -Sarang