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Old   December 11, 2009, 16:00
Default Top boundary condition for fluidized bed
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Hy Guys,

I am simulating a fluidized bed reactor using cfx 11. I am using a kinetic theory of granular flow in order to simulate the behaviour of the catalys phase. Well, I managed to set-up the simulation, and run it, however I get some unnatural results, for example higher pressure on the top of my bed in comparison to my inlet, border between gas and solid oscilates before bubbles appear, and also very high gas velocity in the freeboard zone.

Somehow I have the feeling that this might have something to do with the outlet boundary condition specification.

When I specify outlet boundary condition, I constantly get the message that my both solids and gas are entering the domain, and the wall is put on the boundary.

When I however put the opening bounday condition with pressure specification, simulation runs fine, but I have to specify the concentrations on the other side of the boundary, which is effecting (diluting my reaction products ) my results, and I cant predict reactor outlet.

Does anyone have any advice?

Thanks a lot,

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