Immutability in Cavitation Nuclei Measured in Our Single-foil Cavitation-tunnel of the Institute of High Speed Mechanics

Abstract

For the first step in this series to clarify the cavitation-nuclei-performance of our cavitation tunnels for a single-foil or cascade-foils, we take up a single-foil tunnel of closed type, with which a number of cavitation-performance-tests had been done by the late Prof. F. Numachi. The change of nuclei distribution with time and the corresponding cavitation aspects are carefully observed for two cases with a Clark Y-foil of 4 percent thickness in the test section and without it, for various cavitation numbers σ and incidences α, showing the interesting fact that cavitation nuclei are scarcely changed, even when heavy cavitation occurs around the foil.