Mass Flow

Author:Matthias Boularot

Created on:12 Mar 2025

Last updated on:12 Mar 2025

Mass flow refers to the rate at which mass passes through a given cross-sectional area per unit of time.

Mathematically, mass flow is calculated using the formula:

\overset{\cdot}{m} = \frac{dm}{dt} = ρ \cdot U_{avg} \cdot A

With

$\overset{\cdot}{m}$: Mass Flow Rate. [ $kg \cdot s^{-1}$ ]
$ρ$: Density [ $kg \cdot m^{-3}$ ]
$U_{avg}$: Average Fluid Velocity [ $m \cdot s^{-1}$ ]
$A$: Cross Sectional Area Through Which the Fluid is Flowing [ $m^{2}$ ]

Notice:

According to the principle of mass conservation (also known as the continuity equation), mass is conserved within a closed system. This principle applies to both incompressible and compressible fluids. It therefore can be used to accurately compare flow meters.