Article
Engineering, Marine
Lin Li, Bo Huang, Shuhang Qian, Zhiying Yang, Jianting Zhou, Qingyang Ren, Bing Zhu
Summary: This study investigates the wave damping performance of floating breakwaters on the box-girder superstructure of coastal bridges under extreme wave conditions. The results show that a perforated floating breakwater with specific opening dimensions maximizes the wave damping performance, which is of crucial significance for studying wave attenuation and disaster prevention.
Article
Engineering, Marine
Xinjun Zou, Xinyao Tu, Shun Chen, Zijian Yang, Chuxiong Liang
Summary: This paper investigates the local scouring characteristics and their effects on the bearing capacity of a monopile-friction wheel composite foundation under combined vertical, horizontal, and bending loads. The simulation results show that the shape and extent of the scouring hole are related to the size of the friction wheel. The scouring angle enhances the bearing capacity of the foundation, while an increase in scouring depth weakens its performance.
Article
Engineering, Marine
Ruidong An, Zhenghua Gu, Tong Zhou, Chinghao Yu
Summary: This paper presents a level set re-distancing (NLS) method for simulating incompressible interfacial flows, aiming to preserve mass conservation and accurately predict interface evolution. The method advects the level set function using an advection equation and simulates the re-distancing equation with a proper mass-correction term. The performance and capabilities of the method are verified through benchmark tests and comparisons with existing results.
Article
Engineering, Marine
Menghu Hua, Hua-Feng Ding, Xiang-Yu Yao, Wen-Jin Liu
Summary: This article addresses the fixed-time Nash equilibrium seeking problem for multiple autonomous surface vehicles (ASVs) and proposes two novel seeking algorithms. By utilizing a model-based control algorithm and a hybrid fixed-time event-triggered approach, it is possible to achieve Nash equilibrium within a fixed time and reduce resource consumption.
Article
Engineering, Marine
Mark Francis Warren, Jason Ali-Lavroff, Damien Holloway, Teresa Magoga
Summary: Linear elastic fracture mechanics methods provide a comprehensive representation of crack propagation, but their usage in the design of marine structures is limited. The research reveals significant differences in estimated fatigue life between fracture mechanics methods and SN curve-based methods, and changes in fracture mechanics parameters also have a significant effect on fatigue life.
Article
Engineering, Marine
Ding Liao, Lu Cheng, Jose Correia, Milan Veljkovic, Shun-Peng Zhu, Jasper Winkes, Koen Creusen, Filippo Berto
Summary: Hole patterns are commonly used in engineering design for connections and assembly. This study focuses on the fatigue performance of a downscaled holed thick steel plate, extracted from a novel C1 Wedge Connection. The influence of surface size effect was observed and discussed experimentally.
Article
Engineering, Marine
Junyue Zhang, Zhenhua Zhang, Huiyao Li, Zhiqiang Rao, Hongxing Hua
Summary: This study establishes the relationship between the pressure fluctuation on the outer wall of the pump-jet duct and the source term of the velocity-field in the Turbulent Boundary Layer (TBL). The study investigates the wall-pressure fluctuations caused by source terms in different TBL regions and compares their spatial-temporal distribution through the wavenumber-frequency spectrum. The characteristics of turbulent structures are revealed using the vortex scale and intensity. An empirical spectrum model is developed to estimate the wall-pressure fluctuations. Additionally, the simulation of velocity-field source is performed using the Large Eddy Simulation (LES) numerical method. The study finds that the logarithmic subrange has the primary contribution to the wall-pressure fluctuations, and there is a low-frequency diffusion due to the rotor and pressure gradient. The small-scale vortices corresponding to high-wavenumbers are in the viscous subrange, while the large-scale vortices corresponding to low-wavenumbers are reflected in the viscous, buffer, and logarithmic subranges. The deformation and rotation forms of vortices migration are represented in different subranges of TBL. The empirical spectrum model can qualitatively predict the pressure fluctuations at different positions of the duct wall, providing a reference for engineering applications.
Article
Engineering, Marine
Peng Yu, Jiuchao Chen, Jiale Zhou, Jiang Li, Lie Yu
Summary: This study conducted local scour experiments to investigate the process of local scour around large-scale bridge piers under tidal currents. The results reveal that variations in tidal current velocity and direction significantly affect the depth and shape of the scour pits.
Article
Engineering, Marine
Junpeng Li, Yunsheng Fan, Jiaxian Liu
Summary: This paper investigates a novel neural network adaptive prescribed performance formation control algorithm for multiple underactuated unmanned surface vehicles (USVs) with asymmetric input saturations and unknown external disturbances. The algorithm addresses the underactuated problem of USVs and compensates the model uncertain dynamics using the radial basis function neural network (RBF NN) minimum parameter method. Adaptive techniques are employed to deal with external disturbances and unknown approximation errors. Furthermore, a continuously differentiable asymmetric saturation model is introduced to design the controller, eliminating the influence of non-smooth input saturations. The effectiveness and superiority of the proposed algorithm are verified through contrast simulation experiments.
Article
Engineering, Marine
Shine Win Naung, Mahdi Erfanian Nakhchi, Mohammad Rahmati
Summary: High-fidelity Large Eddy Simulations were used to study the effects of blade oscillation on the unsteady flow behavior and performance of composite marine propeller blades. The results showed that blade oscillation has a significant impact on vortex generation, which could affect the performance and structural integrity of the composite blades.
Article
Engineering, Marine
Zheng Yu, Run Liu, Chengfeng Li, Xintong Hao
Summary: The clarification of the pipe-soil interaction mechanism is crucial for the design of in-situ stability of shallow embedded pipes in subsea areas. This study investigates the effects of horizontal cyclic motion on soil and proposes a method for calculating dynamic embedment depth.
Article
Engineering, Marine
Marco Lamberti, Aurelien Maurel-Pantel, Frederic Lebon
Summary: This paper analyzes the effects of hydro-thermal aging on polyurethane adhesive connections and develops an efficient semi-analytical procedure to evaluate the performance of bonded joints in the marine environment. Experimental investigations are conducted to study the mechanical behavior of bonded connections under accelerated aging conditions.
Article
Engineering, Marine
Shizhe Chen, Jiming Zhang, Shixuan Liu, Bangyi Tao, Yushang Wu, Xiaozheng Wan, Yuzhe Xu, Miaomiao Song, Xingkui Yan, Xianglong Yang, Zhuo Lei
Summary: Marine optical buoys are an effective tool for obtaining ocean optical observation data, and their stability is crucial for operating in complex environments. We propose a highly stable buoy structure that can withstand harsh marine conditions.
Article
Engineering, Marine
Guoshou Zhao, Ning Liang, Qianqian Li, Linlin Cao, Dazhuan Wu
Summary: The effects mechanisms and cavitation oscillations of bio-inspired leading-edge tubercles in a waterjet pump were investigated through experiments, numerical simulation, and modal analysis. It was found that the tubercle design could confine the blade cavitation in the troughs with stable tubular-like patterns and break the spanwise coherent development. The tubercles induced turbulent flow, formed low pressure in the troughs, and caused cavities. Vortex stretching and dilatation due to tubercle cavitation were also observed. The loading instabilities around the tubercles were found to be responsible for dominant oscillations in the blade middle part. The large-scale cavities depression by the tubercles effectively avoided thrust extremes. The thrust energy between smooth and tubercle pumps for a single blade and impeller were found to be similar, indicating the need for further research to mitigate excited force instabilities.
Article
Engineering, Marine
Congshuai He, Junchao Zhu, Wuchao Chen, Tao Wei, Wei Jing, Dakuan Xin, Hongxing Hua
Summary: The Carrera unified formulation (CUF) is used to simplify the three-dimensional dynamic model into a hierarchical one-dimensional model while maintaining accuracy. The study investigates the thermal vibration characteristics of a composite shaft under axial load and analyzes the effects of temperature, structural parameters, and axial load on the vibrational properties. The results show significant influences of these factors on the fundamental properties of the composite shaft.
Article
Engineering, Marine
Mingxin Li, Suyong Pan, Yong Cheng, Zhi-Ming Yuan, Longbin Tao
Summary: This paper establishes a numerical model to investigate the hydrodynamic performance, motion characteristics, and the influence of various parameters on the motion response of ships advancing in waves.
Article
Engineering, Marine
Libo Chen, Yao Yao, Hao Liu, Xin Liu, Wenbing Wu, Guoxiong Mei, M. Hesham El Naggar
Summary: Accurately estimating the horizontal dynamic parameters of offshore pile groups is crucial for offshore foundation engineering. This study considers the hydrodynamic force and dynamic soil resistance induced by pile horizontal vibration, providing a more accurate and comprehensive analysis of offshore twin-pile foundations.
Article
Engineering, Marine
Mingming Liu, Guoqiang Tang, Qin Zhang, Xin Jin
Summary: This paper developed a two-dimensional numerical model to investigate the effects of surface roughness on local scour around pipelines. The results showed that increasing roughness led to a rapid decrease in scour depth, followed by a slower change.
Article
Engineering, Marine
Zhongwan Wu, Jie Gong, Jiangming Ding, Yidan Sun, Chao Ma
Summary: This paper proposes modifications to the propulsion system of the shaftless rim-driven system and an optimization strategy for the stern propulsion system of the modified ship. The results show significant reductions in total resistance, power, and occupied volume for the optimized design.
Article
Engineering, Marine
Kai Wang, Jingfu Peng, Tianhui Liu, Zhiqun Guo, Liangjing Zhong
Summary: In this study, a semi-analytical method was developed to evaluate the stability of air cushion-supported floating platforms (ACSFPs). This method allows for quick evaluation of initial stability and efficient assessment of stability under extreme conditions.
