Equation of Continuity

If an incompressible liquid is continuously flowing through a pipe or a channel (whose cross sectional area may or may not be constant), the quantity of liquid passing per second is the same at all sections. This is known as equation of continuity of a liquid flow. Mathematically,

Q1 = Q2 = Q3 = .....

or

a1v1 = a2v2 = a3v3 = .....