Experimental study and characterization of bubble behaviors in the orifice-induced hydrodynamic cavitation

Experimental studies were performed to characterize the development process of orifice-induced cavitation and transitional bubble behaviors. The transition from non-cavitation to fully developed cavitation was carefully studied. Cavitation bubble clouds were observed at orifice, indicating the inception of cavitation. The number of bubbles produced were dramatically increased while the averaged sizes of bubble reduced when cavitation was initiated. Both orifice opening ratio and perimeter can affect the cavitation developing process. A long orifice perimeter promotes the production of fine bubbles. The orifice plates with the smallest opening ratio generated a desired gas-liquid interfacial area at the lowest required pressure. An orifice plate with multiple orifices is recommended in the design of orifice-based cavitation reactor for production of high cavitation intensity