Abstract

Cavitation is a multiphase flow phenomenon produced when local liquid pressure reaches or falls below the saturation vapor pressure and the resulting vapor structures subsequently collapse or persist according to the downstream pressure field. This article examines cavitation in rotodynamic pumps, control valves and piping systems, marine propulsors, hydrofoils, and hydraulic turbines. The discussion integrates net positive suction head, pressure recovery, cavitation indices, liquid choking, unsteady loading, erosion, noise, vibration, and performance degradation with practical diagnostic and mitigation methods. Particular emphasis is placed on distinguishing the location of vapor formation from the location of collapse, because damage may occur downstream or away from the apparent inception site. System pressure, local velocity, equipment geometry, operating envelope, materials, coatings, and verification methods are treated as coupled engineering variables. The resulting framework supports mechanism based assessment and selection of preventive measures across hydraulic and marine applications.

Keywords: hydrodynamic cavitation; net positive suction head; control valves; hydraulic machinery; marine propulsors; cavitation erosion; pressure recovery; vibration.