Water hammer is defined as which phenomenon?

Water hammer is defined as which phenomenon?

• A. The heat transfer rate in pipe.
• B. A pressure surge caused by the kinetic energy of a moving fluid when it stops or changes direction suddenly.
• C. The steady-state flow of water in a pipe.
• D. The vapor pressure inside pipes during boiling.

Answer: (B)

Water hammer is a pressure surge that occurs when a moving liquid is forced to stop or change direction suddenly. The fluid’s inertia keeps it moving, so when a valve closes quickly or a pump stops, a rapid deceleration creates a pressure wave that travels through the pipe. This abrupt rise in pressure, depending on the fluid, velocity, and pipe properties, can be large enough to cause banging noises, vibrations, or even damage. The effect is described by how the pressure increase relates to the change in velocity and the wave speed in the pipe. This is different from the heat transfer rate, which is about energy moving as heat; from steady-state flow, which is conditions that don’t change with time; and from vapor pressure during boiling, which concerns phase-change pressure rather than dynamic pressure transients.

Water hammer is a pressure surge that occurs when a moving liquid is forced to stop or change direction suddenly. The fluid’s inertia keeps it moving, so when a valve closes quickly or a pump stops, a rapid deceleration creates a pressure wave that travels through the pipe. This abrupt rise in pressure, depending on the fluid, velocity, and pipe properties, can be large enough to cause banging noises, vibrations, or even damage. The effect is described by how the pressure increase relates to the change in velocity and the wave speed in the pipe.

This is different from the heat transfer rate, which is about energy moving as heat; from steady-state flow, which is conditions that don’t change with time; and from vapor pressure during boiling, which concerns phase-change pressure rather than dynamic pressure transients.