Continuity Equation

Conservation of Mass (Continuity Equation):

The continuity equations is a conversation of mass equation for fluid flow. Fluid mass must always be conserved in fluid systems. This holds true for pipes, channels, and various other systems. The idea is that the mass into a system cannot disappear along the way, and an equal amount of mass must exit the system:

where:

or when applied to fluid flow,

and normally you can assume the fluid is incompressible so ρ₁=ρ₂ therefore:

where:

Note: These equations will work as long as you keep your units straight. That way you can use either SI or US as long as you keep everything in order.

Other Variations of the Continuity Equation:

Solve for Flow:

References:

1. To be inserted.