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Old   March 28, 2012, 21:57
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chenxizhong
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hi, I am want to simulate the fluidized bed. I have been used fluent before, but there are so many restrict , which the "real code" cannot be seen . So I decided to used OF . I have read many papers from you and your partner. Excellent work you did! Looking forward to your new paper.

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Originally Posted by alberto View Post
The code is implemented correctly, and, if you use a small-enough time step, it should indeed work. However its stability is not strong.

The typical approach to enforce the packing limit is to:
  1. Remove the singularity in the particle pressure. One way is to use CarnahanStarling radial distribution function (btw, Gidaspow's radial distribution is not correct, since it is not 1 when alpha is zero. The correct version of that formulation for g0 is the one of Sinclair and Jackson).
  2. Use a continuous function to manage the dense (frictional) limit. In such limit, the kinetic theory is not applicable anyways, because collisions are not binary anymore, and there is sustained contact among particles.
  3. Include the effect of the particle pressure into the equation for alpha. OpenFOAM does this if the "ppMagf" model is used. Note that ppMagf is the "elastic modulus" of the phase, which is nothing but the derivative d(pa)/d(alpha), being pa the particle pressure. The same approach can be extended to manage packing limit with the kinetic theory model.
What kind of problems do you need to solve? I could try to merge some of the developments I have in my code into twoPhaseEulerFoam, and release them. After all, they are all written in my paper
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Old   March 28, 2012, 22:02
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Alberto Passalacqua
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Quote:
Originally Posted by chenxizh View Post
hi, I am want to simulate the fluidized bed. I have been used fluent before, but there are so many restrict , which the "real code" cannot be seen . So I decided to used OF . I have read many papers from you and your partner. Excellent work you did! Looking forward to your new paper.
I will try to have a proof-of-concept code by the end of the weekend. The main code we use has unpublished developments, so I have to branch it and remove them.
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