Article
Energy & Fuels
Ziyi Mei, Bo Gao, Ning Zhang, Yuanqing Lai, Guoping Li
Summary: The study of the unsteady flow field characteristics of podded propulsor shows that the pod significantly affects the flow field, resulting in fluctuations in propeller thrust and variations in local lateral force. Under the influence of propeller wake flow, the pressure distribution exhibits a spiral pattern, with complex vortex structures including tip, root, and hub vortices, as well as strut and fin vortices. The vortex structures generated by the mutual inductance effect between vortices are also discussed.
Article
Engineering, Marine
Pei Xu, Chao Wang, Liyu Ye, Chunyu Guo, Chunhui Wang, Weipeng Xiong
Summary: This study investigates the process of cutting ice layers using a dynamically azimuthing podded propulsor through numerical simulation. The research results provide technical support for structural safety analysis and navigation strategy selection of ice-class podded propulsors.
Article
Engineering, Marine
Yaqi Tian, Cong Zhang, Lei Yang, Wu Ouyang, Xincong Zhou
Summary: This study establishes a simulation model to analyze the vibration characteristics and transmission mechanism of podded propulsor shafting, providing theoretical support for reducing vibration and ensuring the safe operation of ships.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Instruments & Instrumentation
Suwen Li, Wanneng Yu, Chih-Cheng Chen, Christopher Chun Ki Chan
Summary: The feasibility of using a POD propulsion system with an electric power system for vessels was tested on a small boat. The system utilizes a brushless DC motor, servo motor, and lithium-ion battery, controlled by a digital signal processor to create an efficient operation in speed and steering. It is expected to provide a basic design for an efficient, stable, and eco-friendly propulsion system for large vessels.
SENSORS AND MATERIALS
(2021)
Article
Engineering, Marine
Jun Yang, Dakui Feng, Liwei Liu, Xianzhou Wang, Chaobang Yao
Summary: This study presents a numerical research on the open-water performance of a pumpjet propulsor at different scales. The results indicate that the efficiency of the large-scale pumpjet propulsor is about 8~10% higher than that of the small-scale pumpjet propulsor. The variations in total thrust and torque coefficient mainly come from the rotor, influenced by the duct and stator.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Marine
Shuaikang Shi, Wanghao Tang, Xiuchang Huang, Hongxing Hua
Summary: The study investigated the inflow turbulence-induced broadband force spectra of a pump-jet using numerical methods. The presence of the pre-swirl stator influenced the spatial flow field and increased the proportion of periodic components in the unsteady force spectra. The results suggest that the amplitudes of the unsteady broadband force spectra for the rotor of the pump-jet are higher than those of the ducted propeller and propeller, although the humps are not as obvious.
Article
Engineering, Marine
Qiaogao Huang, Han Li, Guang Pan, Xinguo Dong
Summary: This study investigates the effects of duct parameters on the open water performance of pump jet propulsor. It finds that the length-diameter ratio and the expansion ratio of duct outlet have significant effects on performance and vortex control, while the tip clearance ratio and the shrinkage ratio of duct inlet have minor effects on performance but noticeable changes in tip clearance flow. The incidence angle has significant impacts on tip clearance vortices, resulting in more considerable performance changes.
Article
Engineering, Marine
Jian Hu, Fugeng Li, Shili Sun, Yingzhu Wang, Qinghao Yan
Summary: This study investigates the unsteady hydrodynamic performance of forward and aft contra-rotating propellers during uniform flow, revealing that strong hydrodynamic interference can lead to load fluctuations and local blade vibrations. The numerical results are validated by experimental data.
Article
Acoustics
Seungnam Kim, Spyros A. Kinnas
Summary: This article investigates the numerical prediction of underwater noise induced by multi-propulsor systems on a flat hull. The hydrodynamic analysis using different propeller configurations is performed to obtain the noise source. The predicted performance is validated and the influence of linear noise terms in the Ffowcs Williams-Hawkings equation is discussed.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Mechanics
Shuaikang Shi, Wanghao Tang, Xiuchang Huang
Summary: This paper investigates the wake flow characteristics and unsteady performance of a pump-jet propulsor under hull condition using Reynolds-averaged Navier-Stokes (RANS) method and large eddy simulation (LES) method. LES method is effective in capturing vortex interactions and shedding processes, leading to low-frequency peaks in fluctuation pressure spectra. Additionally, LES method shows humps near blade passing frequency in rotor unsteady force spectrum, indicating the importance of phase cancelation between different blades for rotor force spectrum.
Article
Engineering, Marine
Antoine Ducoin, Ramona B. Barber, Stuart J. Wildy, John D. Codrington, Aaron Baker
Summary: This paper presents an experimental study on the deformation of a composite propeller blade in a uniform inflow. Real-time strain monitoring was achieved by embedding fiber Bragg grating sensors inside the blade. The experimental setup reduced the effect of the free surface and allowed for accurate measurements. The forces, deformations, and flow detachment regions were analyzed, demonstrating the fluid-structure interaction dynamic.
Article
Engineering, Marine
Jennie Andersson, Robert Gustafsson, Rikard Johansson, Rickard E. Bensow
Summary: Propulsive factors are critical for scaling of model-test data and final power prediction. Understanding the differences in propulsive factors and propeller-hull interaction is important when comparing different propulsion systems based on model-scale tests. This study compares three different propulsion systems using CFD and evaluates the propeller-hull interaction.
Article
Engineering, Ocean
Stefano Gaggero, Mattia Martinelli
Summary: The study analyzed and compared the performances of different Propeller Boss Cap Fins devices designed with optimization methods, uncovering some side effects of conventional PBCF. It was also found that increased hub vortical structures lead to a substantial increase in radiated noise.
APPLIED OCEAN RESEARCH
(2021)
Article
Engineering, Marine
Fuzheng Li, Guanshan Liu, Qiaogao Huang, Guocang Sun, Guang Pan, Denghui Qin
Summary: This study investigates the impact of asymmetric pre-whirl stator spacing on the hydrodynamic performance of a pump-jet propulsor (PJP). The results show that the steady performance is not affected by stator non-uniformity, but the fluctuation of rotor force and flow field is influenced by this adjustment. The different incident angles of each rotor caused by various stator spacing are the main cause. The slight change in stator arrangement does not cause significant flow changes, but reduces the thrust amplitude at specific frequency by 40% compared to the uniform stator case.
Article
Engineering, Marine
Weng Kai Qiang, Wang Chao, Li Peng, Hu Jian, Sun Cong
Summary: The actual working environment of a pump jet propulsor is formed through the joint action of the vessel and thruster. The disturbance created by the pump jet propulsor alters the flow field of the vessel, which in turn affects the hydrodynamic performance of the propulsor. A steady-state substitution relationship is thus established between the two systems. This study developed a numerical model to predict the induced velocity field of the vessel and incorporated it into a model for pump jet propulsor performance prediction, taking into account the vessel body influence.
