Title: Cavitation Characteristics and Infinite-Aspect-Ratio Characteristics of a Hydrofoil Section
Abstract: Abstract This paper describes “two-dimensional” tests in a water tunnel of a profile identical to the 4412 airfoil section of the National Advisory Committee for Aeronautics. The tests included photographic observations of the inception and growth of cavitation as influenced by velocity, pressure (submergence), and angle of attack, and measurements, during cavitation-free operation, of the hydrodynamic forces and moments as functions of Reynolds number and angle of attack. The relation between the angle of attack and the value of the cavitation parameter at which inception occurs is shown for each face of the hydrofoil. The effect of profile geometry in causing cavitation, and the significance of distinctly different types of cavitation obtained with change in variables are discussed. Convenient curves are given showing the submergence required to avoid cavitation for different velocities and angles of attack. The measured hydrodynamic characteristics are presented in graphical form and are also compared with previously existing data from wind-tunnel tests of a finite-aspect-ratio span. The experimental procedure and its reliability in indicating true infinite-aspect-ratio characteristics are discussed.