Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Study on Propeller Cavitation and Hull Fluctuating Pressure &Noise Synchronization Test
Lu Huang, XiaoYong Shi, YiHong Chen, Chaosheng Zheng, Ziying Xiong
China Ship Scientific Research Center
Wuxi, Jiangsu, China

behaviour and the synchronously measured noise at the model scale
was studied by adjusting the frame of high speed video and thesampling frequency of hydrophones. However, this simultaneous
measurement method is just capable of measuring the hull fluctuatingpressure and cavitation pattern or noise and cavitation simultaneously.
In order to obtain the relativity between the cavitation and hull
fluctuating pressure &noise, the synchronization test of high-speed
video for the model propeller of VLOC was carried out in a large
cavitation channel. Through the synchronization test, the relativity
between acoustic and hydrodynamic characteristics can be researched.

ABSTRACT
In order to obtain the relativity between the propeller cavitation andhull fluctuating pressure &noise, the synchronization test of high-speed
video for the model propeller of VLOC was carried out in a large
cavitation channel. Propeller sheet cavitation and tip vortex cavitation
was observed at ballast condition. The tip vortex cavitation wasbursting violently which contributed to the high harmonic blade rateorders of pressure fluctuations. The formation of tip vortex cavitationand the collapse of the sheet cavitation induced the dramatic increase ofsound pressure and hull fluctuating pressure.

1. Propeller design
KEY WORDS: propeller; cavitation; noise; hull pressure;
In order to obtain maximum efficiency and avoid cavitation, the inflow
distribution should be considered before the propeller design. The wake
distribution of VLOC at design condition has a high wake peak and thehigh wake peak changes sharply. Based on the wake distribution,
propeller pitch distribution was designed with a high load in the tipregion. Tip loaded of propeller has more uniform radial load
distribution which can improve open water efficiency. The camber
distribution was designed to match with the pitch. Using the new bladesection design technique, the propeller was designed to get more stablecavitation behavior. The new blade section design technique was basedon the Eppler method which controls the cavitation bucket of profile bychanging the thickness and camber of the airfoil profile. After thepropeller design, open water performance and cavitation behavior weresimulated on model scale. Fig.1 shows the cavitation behavior at ballast
condition which was predicted by CFD.

synchronization test

INTRODUCTION
With the increase of ship speed and high loaded, propeller cavitation isnearly inevitable. When the propeller cavitation occurs, the ship hullpressure and noise become obviously higher than the non-cavitation
condition (Arveso and Vendittis, 2000). Cavitation is a complicatedphenomenon including both hydrodynamic and mechanical aspects,
and it is unavoidable for merchant ship propellers. Ship Propeller
cavitation noise and hull fluctuating pressure investigations mainly
focus on computational prediction methods, few experimental detailed
studies have been reported. To control the hull fluctuating pressure andpropeller noise, it is necessary to study the mechanism by experiment.
In normal case, we carry out propeller cavitation test and hull
fluctuating pressure test &noise test respectively to get the propeller
performance after designing. However, this experiment method cannot
study the fluid mechanism. By means of high-speed video (HSV)
recording and simultaneous measuring of hull pressure time function,
the fluid mechanical connections between propeller inflow velocity
patterns, cavity dynamics and details of propeller–induced unsteadyhull pressure time series characteristics can be derived. Pereia (2004)
and Tukker (2004) already studied the unsteady evolution process ofpropeller vortex cavitation and sheet cavitation, they compared thisprocess with the synchronous test result of hull fluctuating pressure.
Song (2018) carried out a synchronization test of tip vortex cavitationand noise in a cavitation tunnel. The correlation between the cavitation

Fig. 1 Propeller cavitation behavior prediction at ballast condition

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