Experimental study of cavitating flow around a NACA 0012 hydrofoil in a slit channel.

An experimental study of a cavitating NACA0012 hydrofoil with aspect ratio 0.02 in a slit channel was carried out using a high-speed visualization at sampling rate more than 100 kHz. The features of the formation and development of cavities in a quasi-two-dimensional turbulent flow were studied. The most energetic modes of unsteady cavitation flow around the hydrofoil were obtained using dynamic mode decomposition. The presence of the second and third modes in the cavitation flow is shown here for the first time. It was shown that each of these modes corresponds to a certain period of development of the unsteady cavity. Experimental data on the reverse motion of the vapor-gas mixture into the inner region of supercavitation are presented.