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-   -   turblent multiphase flow (http://www.cfd-online.com/Forums/cfx/18986-turblent-multiphase-flow.html)

zhu May 16, 2002 03:20

turblent multiphase flow
 
Hi, all, when i learn cfx4, i have a question about the standard k-epsilon model in turblent multiphase flow, such as gas-solid flow. solid phase turbulent may be laminar, so, what's the equation about k-epsilon model of solid phase? someone know this. thanks. zhu

zhu May 17, 2002 06:11

Re: turblent multiphase flow
 
hi,all, maybe i don't explain my question clearly. when i simulate turbulent two-phase flow, one phase is tubulence ,the other is laminar. cfx manual says 'if any of the phases is laminar, the LAMINAR string turns off the turbulence model for the relevant phase'. but from my results, the code doesn't turn off the turbulence. that the command concerns with the turbulence is

>>OPTIONS

TURBULENT FLOW

>>TURBULENCE PARAMETERS

>>TURBULENCE MODEL

PHASE NAME 'PHASE1'

TURBULENCE MODEL 'K-EPSILON'

PARTICLE INDUCED TURBULENCE 'NONE'

>>TURBULENCE MODEL

PHASE NAME 'PHASE2'

TURBULENCE MODEL 'LAMINAR'

PARTICLE INDUCED TURBULENCE 'NONE'

if the code don't turn off the turbulence ,so what is k-epsilon equation, maybe i am wrong, i don't know. someone have the experience? thanks in advance zhu

cfd guy May 17, 2002 14:35

Re: turblent multiphase flow
 
Once I've read in the manual that both phases must have the same turbulence model, but I also have read this that you mentioned. Perhaps this formulation, turbulence for the continuous phase and laminar for the disperse phase, may be a numerical strategy to "turn off" the diffusive terms in the dipersed phase turbulence equations, perhaps. I don't know.
Regards, cfd guy


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