[zermenos]

Hello,

I am setting up a simulation for a piping system in which I need to simulate the flow through a valve. The valve won't be moving for the whole simulation so it must be a simple boundary condition. I've tried calculating the volume flow myself and setting the flow through this valve as some percentage of this volume flow but this approach tends to be very unstable.

is there any special boundary condition that adjusts the volume flow as a function of an internal variable? say, something like

newVolumeFlow=0.5*volumeFlow

without having to do hand calculations

I would appreciate any help if you have any ideas to approach this problem

thank you

zermenos