Abstract

Hydrodynamic cavitation is increasingly applied as a multifunctional process intensification method in systems where pressure reduction, bubble generation, interfacial renewal, collapse, and repeated hydraulic exposure can be exploited for different engineering objectives. This article evaluates emerging applications in cooling water conditioning, commercial aquatic systems, aeration, flotation, gas stripping, biomass lysis and extraction, petroleum processing, critical mineral recovery, cavitating jet cleaning, and drilling. The analysis distinguishes collapse dominated treatment from stable cavity and microbubble regimes and emphasizes that pressure drop alone does not define process severity. For each application, the relevant mechanism, performance metric, downstream separation requirement, scale up variable, and principal failure mode are identified. Reviewed evidence shows that cavitation can intensify bulk crystallization, oxygen transfer, fine particle flotation, degassing, mass transfer, surface cleaning, and rock weakening when the hydraulic state is matched to the required function. The same mechanisms can also cause erosion, fragmentation, gas redissolution, contaminant release, excessive fines, or unproductive energy consumption. Scale up therefore requires preservation of both local cavitation behavior and system exposure, together with measured flow, pressure, temperature, gas fraction, power, wear, and application specific response. The most defensible design approach is function first: define the required physical effect, integrate cavitation with the necessary separation and control operations, and validate performance under realistic feed variability and extended operation.