The formation and collapse of gas pockets or bubbles on the blade of a centrifugal pump's impeller is known as what?

The correct term for the formation and collapse of gas pockets or bubbles on the blade of a centrifugal pump's impeller is cavitation. Cavitation occurs when the pressure in the pump decreases to a point where the liquid can form vapor bubbles. When these vapor bubbles move into a higher pressure area, such as in the impeller or volute, they collapse violently, creating shock waves that can cause significant damage to the pump components. This phenomenon not only affects the efficiency of the pump but can also lead to physical erosion of the impeller and reduced operational life.

Surging refers to an unstable condition in the flow, typically characterized by fluctuations in flow rate. Backflow involves the unintended reversal of flow in a system, which is not related to gas pockets or bubbles. Vortexing is a condition that may occur when a liquid's flow creates a swirling motion, but it is distinct from the collapse of vapor bubbles that is characteristic of cavitation. Understanding cavitation is crucial for pump operation and maintenance, as it helps to mitigate the risks associated with this damaging process.