Force due to water hammer (Slow valve closure)
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. When the valve is closed slowly compared to the transit time for a pressure wave to travel the length of the pipe, the elasticity can be neglected.
Related formulasVariables
| F | Force due to slow valve closure (N) |
| ρ | Density of the fluid (kg*m-3) |
| L | Pipe length (m) |
| A | Pipe cross section (m2) |
| δv | Change in the fluid's velocity (m/s) |
| δt | Valve closure time (s) |