Cavitation-free buckets of YS-920 and NACA 66 (MOD) foil sections

Based on a wing section design theory and boundary layer calculations, a new series of hydrofoil sections with improved cavitation inception characteristics were theoretically developed and presented in previous papers. To verify these theoretical results experimentally, two hydrofoil models, one a newly developed profile designated YS-920 and the other an NACA-66 (MOD) wing section, were tested in high-speed water tunnel. The measurements included force and moment data, flow visualization, cavitation characteristics, and surface roughness effect on cavitation. In this report, the measured cavitation-free buckets of YS-920 and NACA-66 (MOD) foil sections are presented and compared with theoretical predictions. The ability to achieve a significant delay in cavitation inception with a newly designed profile is clearly demonstrated experimentally.