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Weighted average volume fraction

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Old   January 22, 2007, 15:46
Default Weighted average volume fraction
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Yasser
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Hello,

I am simulating 2-phase solid-liquid flow in mixing tank using Eulerian model. My study concentrate on the concentration of solids in the tank. I have no injections of solids or liquid in the tank (the impeller mixes the 2 phases).

I assumed an initial homogenous mixture with solid volume fraction of 0.04 by patching this value before iteration.

After the solution converged, i found the Weighted average volume fraction is lower than 0.04, it was equal to 0.023.

I tried to turn off the volume fraction equation but,When i turned the volume fraction equation off, the mixture became homogenous as initialized and no particle distribution obtained.

how can i fix the volume fraction of the solid in the whole tank while the concentration still can change??

Thanks for help

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Old   January 26, 2007, 15:41
Default Re: Weighted average volume fraction
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Yasser
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i didn't solve my problem yet

anyone can help
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Old   April 30, 2010, 18:08
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Tantular Nurtono
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I have the same problem in solid-liquid mixing tank using the MRF model for impeller rotation. The solid volume fraction becomes lower and lower during the iteration. Please help us. Many thanks.
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Old   May 1, 2010, 21:49
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Inra Sumahamijaya
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Quote:
Originally Posted by tantular View Post
I have the same problem in solid-liquid mixing tank using the MRF model for impeller rotation. The solid volume fraction becomes lower and lower during the iteration. Please help us. Many thanks.
Similar prolem to Thread Starter, I tried to register the solid phase, and patched the registered solid phase with initial 0.04 volume fraction. Still, not solving the problem, the solid volume fraction becomes lower and lower during the iteration. The worse case is, each iteration took me 2 hours to complete!

I'm using Fluent 12.0
Any help would be greatly appreciated
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Old   May 20, 2010, 21:19
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Inra Sumahamijaya
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I've overcome those non-constant Volume Fraction during iteration problem.

I was using the steady-state method when i encounter the first problem; But after i try to use unsteady state Transient using simple time step and a few iterations in every time step, i had constant a Volume fraction!

Gladly, i solve one problem. But another problem occur. I have a "cracked" contour in my case. I'll explain clearly in a new thread.

Thank you, Hope that helps.
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