Performance and Unsteady Internal Flow of Small Side Thruster for Ship at High Cavitation Number

Abstract

Small thrusters installed on fishing vessels are often operated at high rotational speed near the draft surface, and are therefore prone to cavitation. Therefore, it is important to clarify the occurrence of cavitation and its effect on thrust performance at each-rotational speed, but there have been few studies focusing on these issues. In this study, we conducted experiments using a high-speed camera to visualize cavitation and measure thrust force, and cavitation analysis on a small thruster with a propeller diameter of 190[mm]. This paper reports on the thrust performance and cavitation flow in the high cavitation number region (σ_n=6.3 to 14.2).