We take the control volume to be a horizontal hyperbolic cylinder
bounded by streamlines on the sides with air entering through the large cross-section (section 1)
and the fan located at the narrow cross-section at the end (section 2),
and let its centerline be the x axis. The density, mass flow rate, and discharge velocity of air are
and let its centerline be the x axis. The density, mass flow rate, and discharge velocity of air are
cross-section
located