Help please:Inlet Boundary Conditions!!!
 

Hi CFX users,

I want to specify pressure and mass flow rate at the same time on inlet of a pipe. Is it possible? For example, 15atm and 1.6e-004kg s^-1. Thanks in advance.

David

Re: Help please:Inlet Boundary Conditions!!!
 

Are you simulating compressible or incompressible flow? In incompressible the absolute value of pressure is of no relevance as only pressure-gradients appear in the equations.

Re: Help please:Inlet Boundary Conditions!!!
 

Thanks, Fabian. I am simulating two-phase flow, one phase is gas and the other is liquid.

Re: Help please:Inlet Boundary Conditions!!!
 

Hi David,

It is not possible to define both pressure AND mass flow at an inlet (unless it is a supersonic inlet, it which case it is necessary), nor does it make sense to do so. You will need to specify a pressure boundary condition elsewhere in your simulation (either another inlet, an outlet, or an opening). The pressure field will then be determined based on momentum and continuity.

Regards, Robin

Re: Help please:Inlet Boundary Conditions!!!
 

Hello Robin

Thank you very much for your answer. Now I understand it.

Many regards David