Objectives Aimed at exploring the pulsating pressure characteristics and control schemes induced by propellers of a high-speed three-propeller ship.

Methods Using CFD method to numerically predict the pulsating pressure induced by propellers of the high-speed three-propeller ship. Analyzing spectral characteristics of the pulsating pressure, spatial distribution on the hull shell plate, and the influence of tip distance and propeller speed on the pulsating pressure. Comparing the control effects of cylindrical and arched vibration isolation holes on the pulsating pressure.

Results The results show that the pulsating pressure induced by propellers on the hull shell plate is mainly composed of the blade frequency component, and the spatial distribution characteristics of pulsating pressure are different from those of single-propeller ships. Reducing the propeller speed can significantly reduce the pulsating pressure induced by propellers, and increasing the propeller tip clearance can significantly reduce the pulsating pressure on the hull shell plate. The arched vibration isolation hole not only reduces the maximum pulsating pressure of the hull shell plate above propellers by about 60%, but also has a relatively small impact on the hull structure.

Conclusions The research can provide guidance for the prediction and control of pulsating pressure in high-speed three-propeller ships. Innovations This study systematically reveals the pulsating pressure characteristics induced by propellers of a complex ship type, the high-speed three-propeller ship. The magnitude and distribution of pulsating pressure induced by the side propellers and the center propeller are different. The maximum pulsating pressure on the hull shell plate above the side propellers is nearly 3 times that above the center propeller, and the extreme value is located at 0.02D forward of the propeller disc and 0.08D inward from the shaft axis, while the extreme value of pulsating pressure above the center propeller is located at 0.08D forward of the propeller disc and directly above the shaft axis. There is strong interaction among the three propellers of the high-speed three-propeller ship. The rotation direction of the center propeller and its suction effect on the side propellers affect the pulsating pressure induced by the side propellers. The physical mechanism of interaction among the propellers is elucidated through vortex field analysis. Based on the spatial distribution characteristics of pulsating pressure and its attenuation with tip clearance, an arched vibration isolation hole is set near the maximum pressure point above the side propellers to control the pulsating pressure. Through parameter analysis, an approximate formula for the variation of pulsating pressure with the top height of the vibration isolation hole is fitted, and recommended values for the dimensional parameters of the vibration isolation hole are provided. Reference value The applicability of the CFD method for predicting pulsating pressure induced by propellers of the high-speed three-propeller ship is verified. Comparison with empirical formulas shows that the empirical formula method has large errors when applied to this complex ship type and fails to capture interaction among the propellers. The spatial distribution characteristics of pulsating pressure induced by propellers of the high-speed three-propeller ship are significantly different from those of traditional single-propeller ships. The conclusions can provide a basis for the stern design and propeller configuration optimization of high-speed multi-propeller ships, and lay a foundation for subsequent cavitation-induced pulsating pressure research and experimental validation. Setting an arched vibration isolation hole near the maximum pressure point above the side propellers is a control scheme that minimizes the impact on the hull structure. The effectiveness of the arched vibration isolation hole for pulsating pressure control is verified, the influence of dimensional parameters on the control effect is investigated, and simple engineering design guidelines are summarized, providing guidance for the control of propeller-induced pulsating pressure.