CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   FLUENT (https://www.cfd-online.com/Forums/fluent/)
-   -   2D axisymmetry Vs non-axisymmetry geometry (https://www.cfd-online.com/Forums/fluent/44195-2d-axisymmetry-vs-non-axisymmetry-geometry.html)

aPpA March 21, 2007 10:08

2D axisymmetry Vs non-axisymmetry geometry
 
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.


Sujith March 21, 2007 15:01

Re: 2D axisymmetry Vs non-axisymmetry geometry
 
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.

aPpA March 22, 2007 08:05

Re: 2D axisymmetry Vs non-axisymmetry geometry
 
Thanks fro the reply Sujith, So does that mean performing a non-axisymmetry simulations for a cylindrical domain is not acceptable?


aPpA March 22, 2007 08:26

Re: 2D axisymmetry Vs non-axisymmetry geometry
 
Thanks fro the reply Sujith, So does that mean performing a non-axisymmetry simulations for a cylindrical domain is not acceptable?


Sujith March 22, 2007 08:33

Re: 2D axisymmetry Vs non-axisymmetry geometry
 
for cylindrical geometry axysymmetry is used.


All times are GMT -4. The time now is 02:55.