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-   -   free surface flow in non-inertial reference frame (http://www.cfd-online.com/Forums/flow-3d/27354-free-surface-flow-non-inertial-reference-frame.html)

Tiedingg February 26, 2009 08:37

free surface flow in non-inertial reference frame
 
Hi~

Has anybody ever used Flow3D to simulate fluid slohing (free surface flow )in a non-inertial refence frame? As we know,to set initial fluid volume we have to firstly set gravity vector.Should I set values of gravity in "Gravity" OR "Gravity Field"? Another problem is about boundary conditions.There is an outlet at the bottom of fluid container and the outflow velocity is constant now . I specified constatn pressure on free surface and constant velocity at the outlet(with others "wall"). However,in my simulation, Flow3D told me that this is unphysical for incompressible flow with net volume flux at the mesh boundary. Help~~ Thank you so much.

MC February 26, 2009 20:51

Re: free surface flow in non-inertial reference fr
 
Hi~

If you are using the non-inertial reference frame then you would set the gravity values in "Gravity Field". What this message: unphysical for incompressible flow with net volume flux at the mesh boundary means is there is no open volume for the velocity to go to. So you may want to check the direction of the velocity or that you have a free-surface. You can do this by favorizing with fluid to see if you have a free-surface to begin with or you can check your velocity vectors to ensure the velocity is actually leaving. If all of this looks fine then a look at the prepin would help better understand and resolve this issue.

MC


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