Water hammer (pressure surge)

Description

Water hammer (or, more generally, fluid hammer) is a pressure surge or wave caused when a fluid (usually a liquid but sometimes also a gas) in motion is forced to stop or change direction suddenly (momentum change). A water hammer commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. It is also called hydraulic shock.

Related formulas

Variables

ΔPPressure wave (Pa)
ρDensity of the fluid (kg*m-3)
α0Speed of sound in the fluid (m/s)
ΔVChange in the fluid's velocity (m/s)