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Rahman December 9, 2003 07:37

Presure setting
Would you give some sort of guidelines about simulation of two gas that will be enter into a cylindrical chamber? I have to mainly see the relative portion of each gas and density of this mixture at the different portion of the chamber(mixing pattern).I have to use two inlet for two gas and one outlet.

I am using velocity inlet and pressure outlet boundary condition. It is also possible to use outflow boundary condition instead of pressure outlet condition. Now i am trying with steady,incompressible,laminar,species transport model.Actually high pressure gasses will be enter inside this low pressure(vacuum) chamber.This low pressure is maintain inside the chamber by diffusion pump which is place at outlet.

Pressure value: gas cylinder pressure---5 bar(say); initial chamber pressure-----6e-6 mbar( before entering gasses); Working pressure---3e-3 mbar (after passing gasses inside the chamber);

#Could u kindly let me know details about pressure setting?

#Will i have to consider pressure drop to calculate velocity? it is?..i have to use velocity at velocity inlet and to calculate reylonds number. So far i have used Q=AV to calculate velocity..where Q=flow rate of gasses,A=x-sectional area of inlet and V= velocity of gasses...which gives very low velocity ...thats means very low reylonds number.

#Is it okay to consider gasses as incompressible? coz velocity is not very high enough(very very low w.r.t light velocity)

#i got problem with continuity equation convergence

Thanks for ur time. Regards, Rahman

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