How does a decrease in net positive suction head available (NPSHa) relative to net positive suction head required (NPSHr) typically affect a centrifugal pump's performance?

A decrease in Net Positive Suction Head Available (NPSHa) relative to Net Positive Suction Head Required (NPSHr) leads to cavitation in a centrifugal pump, severely affecting its performance. NPSHa is the absolute pressure at the suction port of the pump minus the liquid's vapor pressure, expressed in terms of head (height of a liquid column). It represents the actual energy available to push the liquid into the pump. NPSHr is the minimum NPSHa....