Flow simulation of a server rack fan (thermo/fluid mechanics)

Hi all,

My work has asked me if I can design a server air inlet port and I they want to make sure it has a certain mass flow going through it. It is basically a vent and I have to make it cheap, strong and with maximum airflow. I have a few designs I would like to test in SW flow simulation, but I am a little lost when determining how to go about it.

My first concern is that the fan performance is measured in mass flow (kg/s). I'm not sure how they measured this because if you stick the fan into a funnel, you definitely won't be getting that same mass flow going through. If I set my inlet to have the same mass flow of the fan, it won't matter what restrictions my vent has and the whole calculation process would be pointless.

Does anyone know the standard for this? Should I be trying to use pressure somehow instead?

Thanks