First, you need to set air as the secondary phase and the sparger as an inlet. Activate the Population balance model. Define the sizes of each class. Finally, you set the fractions fi of each bin (=class) at the inlet boundary. That is, you set 1 for the class that corresponds to 4 mm, all other classes will have the fraction equal to 0. Similarly, set also the initial conditions for fi.

Thank you very much Zbynek Kalal,

In this case, 2nd bin falls on 4mm. Is there any need to patch the inlet Sparger region with value 1 after initialization ? Do you know.. I was following the same procedure, Because from one manual I got the same hint. but unfortunately, Whenever I put Bin-2-fraction value 1 and all other remain zero. there would be a floating point exception error. Although, I also mark a region same as Inlet and Patch Bin-2-fraction value 1. But same floating point exception error because of all bins are zero except Bin-2-fraction.

Error is :

Divergence detected in AMG solver: bin-2-fraction

Divergence detected in AMG solver: bin-3-fraction

Divergence detected in AMG solver: bin-4-fraction

Divergence detected in AMG solver: bin-5-fraction

Divergence detected in AMG solver: bin-6-fraction

Divergence detected in AMG solver: bin-7-fraction

Divergence detected in AMG solver: bin-8-fraction

Divergence detected in AMG solver: bin-9-fraction

Divergence detected in AMG solver: bin-2-fraction

Divergence detected in AMG solver: bin-3-fraction

Divergence detected in AMG solver: bin-4-fraction

Divergence detected in AMG solver: bin-5-fraction

Divergence detected in AMG solver: bin-6-fraction

Divergence detected in AMG solver: bin-7-fraction

Divergence detected in AMG solver: bin-8-fraction

Divergence detected in AMG solver: bin-9-fraction

Divergence detected in AMG solver: bin-2-fraction

Divergence detected in AMG solver: bin-3-fraction

Divergence detected in AMG solver: bin-4-fraction

Divergence detected in AMG solver: bin-5-fraction

Divergence detected in AMG solver: bin-6-fraction

Divergence detected in AMG solver: bin-7-fraction

Divergence detected in AMG solver: bin-8-fraction

Divergence detected in AMG solver: bin-9-fraction

turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 10690 cells

First of all, I would not choose the initial size to be Bin 2 unless you expect nearly pure coalescence since now the bubbles that enter the system can break up only to Bins 0 and 1. But that is problem-dependent. You do not patch anything anywhere. You only set the initial conditions (it should not actually matter really much what you choose since I guess that you have no gas in the system at the beginning of the computation). It is nevertheless advisable (or maybe necessary) to have sum of the bin fractions equal to zero so let's set one of the bins to 1. I choose the bin that enters the system through the inlet. Then you set the boundary conditions at the inlet as I described previously. If you get divergence even after that, the problem is somewhere else, probably in your turbulence model settings. Check that your initial values of k and epsilon (or omega or whatever you use) are non-zero.

Thank you very much sir . . . I got the answer.. there was a problem with turbulence model not bin fractions... thank you again...

Hello Muhammad Furqan Ali...I am also trying to use Population Balance Model for modeling the Bubble Size Distribution in the Stirred Tank Reactor...I want to know how should I proceed..Can you please help....I would be thankful...

Hi Muhammad,

Hope you are fine and doing well. I am also trying to use Population Balance Model for modeling the Bubble Size Distribution in the Stirred Tank Reactor...I want to know how should I proceed..Can you please help....I would be thankful...

Hi, Sohail..

My pleasure.. Can you extract some useful guideline from the attached paper of Stirred Tank Reactor ? Which type of guideline do you need, please tell me step by step.

Regards

Hi Furqan,

Thank you so much for the reply. I will go through the paper and let you know. I will stay in touch.

Hi Furqan,

I would also like to know what was the problem with the turbulence model and which turbulence model you finally used. Please reply.

Thank you!

HI,

I have experience of this error. Actually, There are many divergences in the start of simulation. But after the simulation get stable and residual reaches to about -3 then K- e model gives stability.

I suggest you , Do not enable any turbulence model in the start , after some time of seconds, try to enable K-e turbulent model. . .

Second thing is that, In the first instance, lean down the PBM model without segregation and breakage. similarly, after stability... enable segregation and breakage of particles.

Here, I am attaching my research paper on CFD-PBM coupling. Can you read Numerical Simulation of this paper ?

Article Hydrodynamic Modeling of Ionic Liquids and Conventional Amin...

Good Luck

Hi Furqan,

Thank you so much for the reply. I do also face similar kind of problems when I run the CFD simulation for the stirred tank reactor. I will let you know when I actually run the simulation once again. Anyways congrats for your new research publication.

Thank you!