How to fix an outlet flow rate ?
 

Hi !

I want to simulate a simple case of a tank containing air and water. The water level stays constant over time and I have an inlet of water+air, an outlet of water and an oulet of air. To conserve my level of water I want to fix the outlet of water : How can I do, there are no velocity outlet boudary conditons ?

I tried to set a velocity inlet at the water exit and by UDF set a negative value to the adjacent cells and extrapolate the velocity field to the boundary but I have a segmentation violation...

Any suggestions ?

Thanks

Re: How to fix an outlet flow rate ?
 

You can define the velocity direction without using a UDF. Change the velocity specification method from "Magnitude, Normal to Boundary" to "Magnitude and Direction" or "Components. Then just define the direction of the flow so it is leaving your system.

Hope this helps.

Good luck Jason

Re: How to fix an outlet flow rate ?
 

This works only in single phase configuration. When in multiphase, fixing this kind of boundary conditions leads to a segmentation violation errors at the initialization of the variables.