how to calculate mass flow at pressure boundary

Hugo

Hi Users!

How does Fluent calculate mass flow at pressure boundaries? The user's guide says

m'=sum(density * dot(velocity, area))

but when I try that I get a completely different answer. I've exported node coorinates to calculate area, and cell values of axial and radial velocity, and calulated in excel.

There is a problem the Fluent reports non-zero velocity at the nodes on the walls - could this be related?

Thanks for any clues? Hugo.