A Review of Hydrodynamic Cavitation Passive and Active Control Methods in Marine Engineering Applications

Hydrodynamic cavitation usually occurs in the marine and ocean engineering and hydraulic systems and may leads to destructive effects such as increasing in hydrodynamic drag, noise, vibration, erosion and performance degradation. In the previous studies, different passive and active control methods are used by the researchers to control the unsteady cavitation and its undesirable effects. In this work, different cavitation passive and active control methods for controlling the sheet cavitation, partial cavitation, cloud cavitation and tip-vortex cavitation are reviewed. Regarding the passive methods, different passive flow control methods, including sweep angle of foil, roughness, bio-inspired riblets, V-shaped, J-grooves, obstacles, surface roughness, blunt trailing edge, slits, various vortex generators and triangular slot are discussed. Regarding the active methods, various active flow control technologies, including air injection, water injection, polymer injection, synthetic jet actuator, piezoelectric actuators and so on are reviewed. It can be concluded that the passive and active methods separately able to control the unsteady cavitation. However, in the severe conditions of the cavitation and higher angles of attack, the passive control methods can only mitigate some re-entrant jets expanding in the streamwise direction and proper control of the cavity structure can not be achieved. In addition, active control methods mostly requires additional energy and, consequently, leads to higher costs. Combined passive-active control technologies was suggested by author, using the strengths of both methods, to suppress cavitation and control the cavitation instability for broad range of cavitating flows efficiently in the future works.