Water hammer (wave speed)
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. The wave speed due to the peak pressure, if the valve is closed abruptly, depends on the fluid compressibility
Related formulasVariables
| α0 | Wave speed at the peak pressure (m/s) |
| K | Bulk modulus of elasticity of the fluid (Pa) |
| ρ | Density of the fluid (kg*m-3) |
| V | fluid's velocity (m/s) |
| a | Wave speed (m/s) |
| E | Elastic modulus of the pipe (Pa) |
| D | Internal pipe diameter (m) |
| t | Pipe wall thickness (m) |
| c | Parameter due to system pipe-constraint condition on wave speed (dimensionless) |