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three phase problem in packed bed

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Old   December 18, 2003, 19:05
Default three phase problem in packed bed
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Janice
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I am simulating three-phase problem - air, water cocurrent flow through a bed of solid catalyst. First step is looking at the flow behavior like pressure drop, gas void fraction, etc. Should i use two phase simulation with porous zone or true three phase simulation? What kind of model is approprate, Mixture or Eulerian?
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Old   December 18, 2003, 23:32
Default Re: three phase problem in packed bed
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ap
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I think you should simulate your system using a three phase simulation, specifing the granular phase with the Packed Bed option enabled (FLUENT 6.1).

I'd suggest the Eulerian model.

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ap
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Old   December 21, 2003, 05:38
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i see, i used fluent 5.2, i dont know if new fluent can simulate 3 phase,:P
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Old   December 21, 2003, 08:59
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Yes. Fluent 6.0 and 6.1 implement the Eulerian-Eulerian multiphase model, which allows you to model a general number of phases, including granular ones, which can be described with the kinetic theory approach.

Anyway the option for packed bed is only present in FLUENT 6.1.

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ap
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Old   December 21, 2003, 19:35
Default Re: three phase problem in packed bed
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thank you, do you know the journal to guide for modeling heat transfer in paralel flow pipe?
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Old   January 5, 2004, 13:56
Default Re: three phase problem in packed bed
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Thank you, AP. Have you tried this problem before? Did you experience any convergence problem with 3 phase Eulerian model? What do you think if i use two phase model like VOF with the porous media option on?
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Old   August 12, 2010, 03:49
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Kevin.J.B.Cheung
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I am a little late to reply. But I think you should use two phases and eulerian to do with your problem.
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Old   October 5, 2010, 08:48
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Subhasish Mitra
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Hi,

I've tried to model a Trickle Bed reactor by both options 1) Three phase eulerian 2) 2 phase eulerian with porous media. Both simulations had convergence problem.

Problem for Gas & liquid phase is how to define the bubble dia considering gas is continuous phase.

For the 3 phase case, I patched solid vol fraction i.e. (1 - bed voidage ) in the solution domain, but to my surprise, solid volume fraction keeps on changing and eventually get replaced by the liquid & gas which is not correct.

Anybody has any clue?

Response will be appreciated.
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Old   October 14, 2010, 08:46
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Try to set the solid to be packed bed
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Old   April 2, 2015, 02:04
Default CFD in Trickle Bed reactor
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Rahul omar
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Hi,

I've tried to model a Trickle Bed reactor by both options 1) Three phase eulerian 2) 2 phase eulerian with porous media. Both simulations had convergence problem.

Problem for Gas & liquid phase is how to define the bubble dia considering gas is continuous phase.

For the 3 phase case, I patched solid vol fraction i.e. (1 - bed voidage ) in the solution domain, but to my surprise, solid volume fraction keeps on changing and eventually get replaced by the liquid & gas which is not correct.

Anybody has any clue?

Response will be appreciated.

email- omar.rahul51@gmail.com
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Old   December 9, 2015, 04:42
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Liam
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What about fixing the velocities of your solid particles in the whole domain to 0?

Also I have read that two phase flow with porous media does not work well in FLUENT, unless you set relative permeabilities via UDF.

The question is that I have tried to model a fixed bed inside a tube using:

1 Three phase flow
2 Single phase flow (with species transport describing my mixture) and porous media for the fixed bed of solid particles using Blake-Kozeny equations for alpha and C1 (based on solid concentration and diameter of solid particles), but I have found that quite different values (for pressure drop for instance) are provided by each model.

Am I missing something or should this two models lead to similar results?
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