Cavitation flow characteristics on the surface of hydrofoil with microjet structure

A hydrofoil physical model is established based on the surface microstructure to mitigate the detrimental effects of cavitation phenomena on hydrodynamic machinery, such as cavitation erosion or surface damage. Tangential microjet structures are arranged on the hydrofoil's surface, and the modified k-omega shear stress transport (SST k–ω) turbulence model is employed to simulate the hydrofoil numerically. This simulation aims to analyze the effects of different chordwise positions and widths of microjet structures on the cavitation flow and performance of hydrofoils. The mechanism of cavitation suppression is revealed by coupling the chordwise position and width of the microjet structures. The results indicated that the chordwise position of the microjet structures near the trailing edge of the hydrofoil has a minimal impact on the hydraulic properties. The optimal chordwise positions are 0.5c and 0.6c, with the deviation rate of the lift-drag ratio within 3%. The optimum jet width is 0.5 mm, and the cavitation suppression is approximately 15% of the prototype hydrofoil. The microjet structures with tangential jets suppress cavitation by creating obstruction and suppression of the re-entrant jet. The tangential jet ratio of 0.3 represents the most effective tangential jet hydrofoil scheme, and the addition of tangential jets produces a significant inhibitory effect on the shedding of large-scale cavitation.