The mass flow rate of a system is a
measure of the mass of fluid passing a point in the ( ˙
m) system per unit time.
The mass flow rate is related to the volumetric flow rate as
shown in Equation 3-2
where r is the density of the
If the volumetric flow rate is in cubic feet
per second and the density is in pounds-mass per cubic
foot, Equation 3-2 results in
mass flow rate measured in pounds-mass per second. Other
common units for measurement of
mass flow rate include kilograms per second and pounds-mass
Replacing V in Equation 3-2 with the
appropriate terms from Equation 3-1 allows the direct
calculation of the mass flow rate.
The water in the pipe of the previous example
had a density of 62.44 lbm/ft3.
Calculate the mass flow