Experimental study on low-frequency flow noise at the stern of a surface vessel induced by pulsating pressure

Abstract

Understanding of the flow noise generated by high-speed ships is limited compared with that of underwater vessels. To better understand the low-frequency flow noise generated at the stern of high-speed vessels, a series of high-speed ship models were designed, and the flow noise induced by the pulsating pressure at their sterns was obtained in tests using 11 high-frequency pressure sensors located at the base of the stern in the longitudinal and transverse directions. The experimental setups and methods by previous researchers were considered. Systematic model tests were conducted under different velocity, side immersion depth (Tside), deadrise angle, and interceptor (which are widely used for high-speed vessels) conditions, and the sound pressure levels under different conditions were calculated. The general characteristics of the flow noise generated at the ship's stern, the influence of key factors, such as velocity, Tside, deadrise angle, and interceptor height, on the relative pressure, and the overall sound pressure level were then examined, providing useful insights for reducing the level of flow noise. The results are useful in obtaining a better understanding of the characteristics of the flow noise of high-speed ship induced pulsating pressure.