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-   -   [GAMBIT] Gambit & 3d open channel flow mesh problem (http://www.cfd-online.com/Forums/ansys-meshing/72603-gambit-3d-open-channel-flow-mesh-problem.html)

 esgee February 11, 2010 11:53

Gambit & 3d open channel flow mesh problem

Hi,

I'm new to CFD and I couldn't find any solution with the Gambit tutorials I looked. My problem is that I have an open channel where water is flowing to a container. Here is very simple picture about it

http://img14.imageshack.us/img14/2968/channelt.png

The flow is surrounded by three walls and air where atmospheric pressure is acting. I'm having problems how to mesh the system (channel + container) 3D grid. I would appreciate any comments, thanks in advance.

 -mAx- February 12, 2010 03:06

what kind of problems?

 esgee February 12, 2010 03:20

I am living in thought that only closed volumes can be meshed. My channel is open to air on its one face so how can I mesh its interior? Is multiphase flow (water and air) the only solution?

 -mAx- February 12, 2010 04:15

you need definitively a closed volume.
Yes Multphase flow

 esgee February 12, 2010 14:21

Would this solution work:
I'll set to the boundary conditions that the three walls are stationary and on the fourth wall, there is no shear stress

 -mAx- February 15, 2010 01:50

you are talking about the fluent side (BC etc...) and you can open a new thread in the right subcategory (I don't have any experience with open channel) , but you need first a 3d mesh

 subha_meter August 1, 2010 11:28

open cahnnel flow

You need a "volume : brick" to assign the computational domain. You can try applying "wall" BC at 3 sides and "Pressure outlet" on the top surface and provide atmospheric pressure condition over there.

For IN, you can use "mass flow inlet/velocity inlet" & for OUT...."outflow" BC.

For open channel flow, you need to use VOF multiphase model to track air/water interface.

 hossein65 April 10, 2012 00:51

Hi;
The best B.C for upper side of an open channel is "symmetry".
that also helps the free surface level change automatically.

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