[cspectre]

I am studying CFX tutorial 9, flow through a pipe with a butterfly valve.

In this tutorial, the flow is assumed to be incompressible.

I'm trying to find out when its necessary to use mass flow averaging over area averaging.

My question is, which averaging method (area averaging or mass flow averaging) would provide the best results for calculating the average pressure at a location down the pipe, and why?

In addition, which would be most suitable to calculate the average velocity and why.

Its the why thats the main thing im trying to find out. Am hoping some knowlegeable people out there can help me!