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how to improve convergence for fine mesh E-E model for fluidized bed?

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Old   May 24, 2012, 02:12
Unhappy how to improve convergence for fine mesh E-E model for fluidized bed?
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the convergence is 1e-8s! and takes ages (literally) to get 0.1s of simulation- its a solid bed with freeboard above and gas velocity inflow bc at bottom.
even 1e-7,1e-6s time step would make a huge difference. any tips??
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Old   October 7, 2012, 17:01
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How many phases are there in your simulation? what is the number of transport equation which should being solved and the degree of coupling? hence, you should enter 1e-3 for absolute criteria of continuity, and enter 1e-5 for time step at first simulation, before this procedure you must simplify your problem.
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Old   October 9, 2012, 14:39
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Quote:
Originally Posted by sadeghsalehi View Post
How many phases are there in your simulation? what is the number of transport equation which should being solved and the degree of coupling? hence, you should enter 1e-3 for absolute criteria of continuity, and enter 1e-5 for time step at first simulation, before this procedure you must simplify your problem.

hi
i am simulating a fluidized bed. i have a problem. there is reversed flow at outlet boundary and the solution does not converge. how can i solve this problem.
Thank you in advance
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Old   October 9, 2012, 15:34
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be sure the gravity is activated
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Old   October 9, 2012, 15:39
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Quote:
Originally Posted by sadeghsalehi View Post
be sure the gravity is activated
thanks alot
i activated gravity in general setting
should i active gravity in operating condition?
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Old   October 9, 2012, 15:47
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Quote:
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be sure the gravity is activated
it seems that you have enough experience in fluidized bed modeling. may I have your E-mail address?
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Old   October 9, 2012, 15:52
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yes it must be activated in operating condition panel
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Old   October 10, 2012, 05:45
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Hello All,

I want to do analysis of heat transfer from water flowing through pipes submerged inside concrete. I am modelling in GAMBIT and wish to analyse it on Ansys FLUENT.

Can anybody help me out, how to model and simulate?

Does any tutorials exist?
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eularian-eularian model, fluidized bed, very slow convergence

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