Hi, I am trying to simulate two-phase flow in cylindrical airlift reactor using both axisymmetry and non-axisymmetry 2D domains. My question is how Fluent assumes the non-axisymmetry domain? (i.e., cylindrical or rectangular or just as a plane surface).

I found out that when I use an axisymmetric domain, the calculated flow rate (based on the surface area) in and out of the domain is the same as FLUENT reports. However, for the same inlet conditions, the flow rates reported by FLUENT in 2D non-axisymmetry simulations are not same as those calculated by me. I back calculated these reported flow rates and found that they corresponded to the value of inlet length (diameter) taken as the surface area. For example if the diameter of the inlet is 0.1 m, the flow rate reported by fluent is based on 0.1 Sq. m. area while the area should actually be = Î *R2 = Î *(0.1/2)2

When i compare the predictions, the axisymmetry results compare very well with experiments but the non-axisymmetry results do not. I was expecting both the simulations results to be same. Could anyone explain about this discrepency? any help is greatly appreciated.

2D with out axisymmetry is a domain without any gradient along z direction. I fluent it report as a domain with 1 m thickness in z direction.

Thanks fro the reply Sujith, So does that mean performing a non-axisymmetry simulations for a cylindrical domain is not acceptable?

Thanks fro the reply Sujith, So does that mean performing a non-axisymmetry simulations for a cylindrical domain is not acceptable?

for cylindrical geometry axysymmetry is used.