What factor affects the pressure rise in water hammer events?

In water hammer events, the pressure rise is influenced by several factors, including pipe diameter, fluid temperature, and flow velocity, making the comprehensive choice a valid one.

The pipe diameter plays a crucial role in determining the flow area and resistance to fluid movement. A smaller diameter may accelerate the fluid when a sudden change in flow occurs, leading to a more significant pressure surge due to the increased velocity changes.

Fluid temperature affects the density and viscosity of the liquid. As temperature increases, the density decreases, which can alter the dynamics during a rapid stop of flow. The changes in temperature will affect the speed of sound in the fluid, consequently influencing how quickly pressure waves propagate through the liquid.

Flow velocity is directly tied to the momentum of the fluid. When flow is suddenly stopped or changes direction, the kinetic energy associated with this movement needs to be transformed, causing pressure spikes. High velocity increases the magnitude of pressure changes during such events.

Therefore, since all these factors contribute to the dynamics of water hammer and pressure rise, their collective influence justifies the choice that all of the mentioned factors affect the pressure rise in water hammer events.