Boundary conditions
 

I have a doubt regarding BC.

I have abox to which flow is coming and ther are 5 outlets thru flow is going out. at the outlets I dont know the any condition. Inlet I know the massflow rate.

What should be the BC at outlet?

Re: Boundary conditions
 

You have to know either the pressure at each outlet or the proportion of the total massflow going through each outlet. Otherwise the simulation is not well-posed: your boundary conditions are not sufficient to specify a unique flow-field.