Parallel run in fluent for multiphase flow

apurv · August 2, 2011, 23:12

Hi all,

I am trying to run a multiphase flow (solid-fluid Eulerian model) case on a cluster with 4 processors. I have noticed that the solids momentum and energy equations are not solved since the residuals are all zeros. And the run diverges prematurely as compared to serial run of the same case. I am not able to figure out why Fluent is not solving the solid's equations in parallel run. Any help is highly appreciated.

Regards,

Apurv

zino · August 3, 2011, 08:48

I want to ask you one thing. how you are modeling solid-fluid model. I did it takes too much time to converge solution. have your solution converged for single process?

apurv · August 3, 2011, 20:44

Hi Zino,

Converged solution depends on lot of factors. The under-relaxation factors have to be just right along with the correct upwindings. I had to play around a lot to fix the urel factors and have used mostly 2nd order discretizations. I am modelling a fluidised bed and so the solid friction model and the packing limit had to be adjusted to get a consistent converged solution for unsteady flow.

Key is to have patience and keep trying. It helps to have experimental results at hand to compare the results.

I hope this helps.

Apurv

August 2, 2011, 23:12	Parallel run in fluent for multiphase flow	#1
apurv New Member Apurv Join Date: May 2011 Posts: 10 Rep Power: 15	Hi all, I am trying to run a multiphase flow (solid-fluid Eulerian model) case on a cluster with 4 processors. I have noticed that the solids momentum and energy equations are not solved since the residuals are all zeros. And the run diverges prematurely as compared to serial run of the same case. I am not able to figure out why Fluent is not solving the solid's equations in parallel run. Any help is highly appreciated. Regards, Apurv

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August 3, 2011, 08:48		#2
zino New Member zino Join Date: Mar 2010 Posts: 23 Rep Power: 16	I want to ask you one thing. how you are modeling solid-fluid model. I did it takes too much time to converge solution. have your solution converged for single process?

August 3, 2011, 20:44		#3
apurv New Member Apurv Join Date: May 2011 Posts: 10 Rep Power: 15	Hi Zino, Converged solution depends on lot of factors. The under-relaxation factors have to be just right along with the correct upwindings. I had to play around a lot to fix the urel factors and have used mostly 2nd order discretizations. I am modelling a fluidised bed and so the solid friction model and the packing limit had to be adjusted to get a consistent converged solution for unsteady flow. Key is to have patience and keep trying. It helps to have experimental results at hand to compare the results. I hope this helps. Apurv