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-   -   Axisymmetric pipe model confusion (http://www.cfd-online.com/Forums/fluent/39110-axisymmetric-pipe-model-confusion.html)

 Ahmed January 3, 2006 06:57

Axisymmetric pipe model confusion

Do we have to model the half pipe horizontally? Because if we make it vertical the symmetry axis boundary will be parallel to (or on) the y axis and the velocity inlet that we define becomes radial rather than axial.

Axial means parallel to the axis and we need it to be axial. It is easy when the half pipe is horizontal. But in my model, because I want to see the gravity effects when the pipe is vertical, does FLUENT make the correct calculations for the "axisymmetric flow 2d" while the radial velocity is the value I give for velocity inlet?

 kp January 3, 2006 08:45

Re: Axisymmetric pipe model confusion

For velocity you need to divide your velocity with inlet dispersed phase volume fraction.

 Ahmed January 3, 2006 10:45

Re: Axisymmetric pipe model confusion

hi!

What do you mean by that?

 Aidan January 3, 2006 11:07

Re: Axisymmetric pipe model confusion

set the problem up as a horizontal pipe. The effects of gravity in the axial or radial direction are included by specifing the direction of gravity in the operating conidtions panel. For example, for a vertical pipe, gravity for the x-direction is set to -9.81 and 0.0 for y-direction.

 Ahmed January 3, 2006 17:30

Re: Axisymmetric pipe model confusion

Very interesting thing happens when I do that. (gx=-9.81 and gy=0 in the operating conditions window)

The results do not change. All the same. Even the iteration number for convergence is same.

Am I missing something or do we change the gravity from another menu? I have checked what i do 2 times and it is still the same. Did you try that?

Thanks again... Anybody.

 Goutam May 26, 2014 07:41

Quote:
 Originally Posted by Ahmed ;127404 Hi and thanks for your answer Aidan. Very interesting thing happens when I do that. (gx=-9.81 and gy=0 in the operating conditions window) The results do not change. All the same. Even the iteration number for convergence is same. Am I missing something or do we change the gravity from another menu? I have checked what i do 2 times and it is still the same. Did you try that? Thanks again... Anybody.
Dear Ahmed, I did the same thing, but I found the results doesn't change. Did you able to solve this issue? Thanks for your time.

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