Hi

How can i calculate mass flow rate at the out let of my tunnel for unsteady flow. I need to specify mass flow rate at the out let of my tunnel for unsteady flow. Thank you very much you are lovely people.

one way that i can suggest, in cfx-post, go to function calculator then select the specific boundary location or (whatever location you want...e.g. plane) from the drop-down menu for location and choose the option to calculate mass flow rate for the specific fluid.

But this option will require the result file or transient result file to be imported in CFX-post. If you want to monitor at every time step during simulation then you can think about creating an CEL expression to calculate it for you. I have not used CEL so far so may be other experienced user can suggest itin a better way.

But one question? if you want to specify mass flow rate at outlet, why do you want to calculate it?

you can monitor the mass flow rate during the run by creating a new monitor in the solver manager and select P-mass boundary flow on outlet as plot variable

Hi KK thanks for your answer. I want to use periodic boundary condition for my case. For that i need to specify mass flow rate at the outlet of my duct to drive the flow.

Martins thank you for answer. Another question, what is P-mass?

You are such a lovely people. I love you all so much.

CFD fanatic

P-mass = Mass conservation equation formulated as a function of Pressure.

Hi cyclone can you give me expression for it. I am using periodic boundary conditions. I love you all so much especially you cyclone.