Conditions required to establish mass flow/volume flow

Hi,

I am in the process of carry out some more CFD analysis on an intake manifold and I can get all the usual pressure & velocity results but I am unable to produce mass/volume flow results.

Can anyone chime in and provide me with some tips on what boundary conditions, and anything else that is required, to produce mass/volume flow results

Thanks,

Ariel

SolidworksFlow Simulation