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-   -   Modelling Slurry flow (http://www.cfd-online.com/Forums/fluent/84134-modelling-slurry-flow.html)

sandisk January 20, 2011 19:02

Modelling Slurry flow
 
My work is to use mixture model in multiphase flow to simulate slurry flow in straight pipe.The slurry is of water and 0.02476 in. sand particles(5 %). My simulation is not converging. I am not sure which drag functions and other functions to use. Has anyone simulated slurry flow with mixture model ? Please help .. or we should use eulerian model only ?

Nikolopoulos January 21, 2011 13:00

Use mixture model is the slip velocity between phases is small and not important.

Use Euler if not.

You are using an unsteady solver?

sandisk January 21, 2011 13:15

The slip velocity between particles is not important, I have unchecked that option. I need to find the pressure drop in the pipe.I am not getting covergence with Euler model too, I tried Schiller naumann drag function and also gidaspow model. I am not sure which options of drag function to select in mixture model. Have you any experience in modelling slurry flow in straight pipes ?

sandisk January 21, 2011 13:17

I am not using unsteady solver, I am using steady state solver .. Should I use unsteady state ?

Nikolopoulos January 21, 2011 13:36

I 'm experienced in Euler - Euler granular flows. I'm working in CERTH/ISFTA in EMMS scheme which is a sub-grid drag model.

I'm not familiar with mixture but i know its limitations.

For sure go to unsteady even if the physics of the problem is steady.
The only way to go steady is with these new pressure-velocity coupling schemes of Fluent 12 but i don't recommend them.

sandisk January 21, 2011 13:44

Thanks, I had treid the Euler model. But I am not getting convergence,I am not sure where I am going wrong. Can you help me look at my case file, if you can. I am stuck in this problem for last 1 week and I am not going any ahead. If I am able to simulate with Euler model, it will be some progress. Will be really gratefull if you can help me with eulerian model ? pls let me know if it is covenient with you ? Thanks for your help ?

manowars October 28, 2014 02:23

Dear Nikolopoulos,

I am coding the EMMS global using paper of W. Wang and J. Li (2007). I guess, your EMMS model is EMMS/matrix?

What value of eps_mf? I used 0.4

Can you suggest which value of convergence criteria for hydrodynamics should be suitable? (I am using 1e-3, but it is not converged for eps_g < 0.6)

Can you recommend how many step for each loop? (I am using 20(steps for eps_gc)x20(steps for eps_gf)x1(a_f = -9.8)x100 (for a_c))

Thank you and best regards,


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