Article
Engineering, Ocean
Jiasheng Li, Yegao Qu, Yong Chen, Hongxing Hua
Summary: The paper presents a numerical method for analyzing the hydroelastic behaviors of fully coupled marine propeller and shafting system immersed in water, using a panel method and a finite element method. A modal reduction technique is utilized to overcome the low numerical efficiency caused by the propeller's asymmetric added matrices. The validity of the method is confirmed by comparing the results with finite element analysis solutions, showing the importance of considering the coupling of fluid, propeller, and shaft for predicting dynamic system responses.
APPLIED OCEAN RESEARCH
(2021)
Article
Engineering, Marine
Jiasheng Li, Yegao Qu, Zhengyi Zhang, De Xie, Hongxing Hua, Junyun Wu
Summary: The hydroelastic responses of the propeller-shafting system in the wake of ships are predicted using a combined panel approach and finite element method. The accuracy of the proposed technique is verified by comparing with numerical solutions. It is found that the fully non-penetration boundary condition is necessary for predicting the hydroelastic dynamics of the propeller-shafting system, especially for high skew propellers. Considering the fluid and propeller-shaft system interaction can significantly affect the amplitudes of exciting forces.
Article
Engineering, Marine
Yulong Zhou, Bin Xiao, Shuangxia Shi, Cao Gao, Zhigang Liu
Summary: This paper discusses the effects of turbulent flow on vibration structure and establishes a mathematical model to accurately predict these effects. The results show that the updated model can greatly enhance computational accuracy, especially for higher modes. The relationship between the dynamic behavior of the shell vibration and the velocity of turbulent fluid is explored, and critical velocities can lead to buckling instability of FIV systems.
Article
Engineering, Marine
Jiasheng Li, Yegao Qu, Yong Chen, Hongxing Hua, Junyun Wu
Summary: This article discusses the effects of different boundary conditions on the wet mode frequencies and added damping of marine propellers. The results show that the completely non-penetration boundary condition must be applied to analyze the wet mode frequencies of lightweight propellers, while the first and second boundary conditions overestimate the added damping.
JOURNAL OF MARINE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Marine
Chang-Lin Meng, Zhi-Jun Shuai, Tao Yu, Ke-Xin Ren, Jie Jian, Xi Wang, Dong-Hua Wang, Wan-You Li, Chen -Xing Jiang
Summary: In this paper, the unsteady exciting characteristics of a marine propeller influenced by the shafting whirling vibration effect are numerically studied by employing the dynamic sliding multi-region method and a Reynolds-averaged Navier-Stokes equation model. The propeller and shafting system inevitably vibrates during operation, where the multiple exciting forces can cause the shafting to rotate and whirl around different center lines at the same time. The influence mechanism of different whirling motions on the propeller exciting characteristics and propeller velocity field fluctuation are studied.
Article
Engineering, Marine
Ali Hammoud, Jihad Sahili, Mervat Madi, Elsa Maalouf
Summary: This paper proposes an efficient and simple numerical method to calculate the added mass and damping parameters needed in the initial design of a ROV, using simulations of free harmonic damped oscillations and software tools like COMSOL Multiphysics and ANSYS FLUENT. The experimental measurements compared well with the potential theory calculations for added mass terms, with relatively small differences, while damping parameters were obtained through fitting functions related to damping force and linear/angular velocity calculations.
Article
Multidisciplinary Sciences
Jie Liu, Tianyang Deng, Xingshan Chang, Feng Sun, Jianhui Zhou
Summary: A study was conducted on the suppression of longitudinal vibration in underwater vehicle shafting using particle damper in order to reduce vibration level and improve silence and stealth. A model of rubber-coated steel particle damper was established using discrete element method and PFC3D simulation software. The effects of various factors on system vibration suppression were analyzed, and a bench test was carried out for validation. The research revealed the mechanism of longitudinal vibration suppression, established the relationship between total energy consumption and vibration reduction, and proposed an evaluating method for the effect of longitudinal vibration suppression.
SCIENTIFIC REPORTS
(2023)
Article
Engineering, Marine
Weipeng Zhang, Fugeng Li, Jiachen Ma, Xiaoshen Ning, Shili Sun, Yulong Hu
Summary: This study examines the rudder vibrations induced by propeller wake and finds that the rudder undergoes span-wise bending under the load induced by the wake. The vibrations of the rudder are related to the excitation frequencies and natural frequencies, with clear characteristics of lock-in regime. The vibration behavior varies at different frequencies.
Article
Mechanics
A. A. Korobkin, T. I. Khabakhpasheva, K. A. Shishmarev
Summary: This study investigates the eigenmodes and eigenfrequencies of two-dimensional elastic structures in contact with a liquid using the linear theory of hydroelasticity. It calculates the shapes of structural vibrations and the hydrodynamic loads simultaneously. By solving a matrix equation, the wet modes, represented as superpositions of dry modes with coefficients obtained from an added-mass matrix, are determined. The study explores the relationships between wet and dry modes and their frequencies, which depend on problem parameters.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Marine
Chang-Lin Meng, Lie-Yi Dong, Dong-Hua Wang, Jia-Xuan He, Zhi-Jun Shuai, Wan-You Li, Shi-Wei Ni, Chen-Xing Jiang
Summary: This study investigates the unsteady propeller hydrodynamic excitation influenced by shafting whirling vibration under different nonuniform inflow conditions. The results show that the two-way coupling affects the amplitude and phase of the excitation, while the frequency remains unchanged. The radial excitation amplitude increases by 31.65% after considering the two-way coupling.
Article
Engineering, Multidisciplinary
Jabbar Firouzi, Hassan Ghassemi, Mohammad Shadmani
Summary: This paper investigates the torsional-longitudinal vibrations of marine propeller shafting systems by developing an integrated mathematical formulation, considering lumped effects on the main shaft and blade deformations. The non-FEM distributed-parameter modeling and Galerkin method are employed to analyze the problem, showing that taking blade deformations into account is advantageous for vibration analysis.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Engineering, Marine
Jiasheng Li, Yegao Qu, Yong Chen, Hongxing Hua, Junyun Wu
Summary: This paper focuses on the development of a three-dimensional panel method combined with the finite element method for analyzing the hydroelastic responses of rotating marine propellers in the wake of ships. The fully non-penetration boundary condition imposed on the deformed blade surface is found to be crucial for predicting the unsteady performance of elastic propellers, as it affects the added damping predicted by considering different non-penetration boundary conditions.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART M-JOURNAL OF ENGINEERING FOR THE MARITIME ENVIRONMENT
(2022)
Article
Engineering, Mechanical
Mehrdad Raisee, Michel J. Cervantes
Summary: The hydrodynamic added effects resulting from fluid-structure interactions have a significant impact on the dynamic response of mechanical systems. This study aims to develop a unified methodology for identifying these effects accurately. The proposed model is based on the least squares solution of an over-determined system of equations using singular value decomposition, which allows for the determination of added inertia and stiffness without assumptions. The method is validated using analytical solutions and applied to challenging fluid-structure interaction test studies.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Engineering, Marine
Songxing Huang, Zhiqiang Hu, Chaohe Chen
Summary: In this paper, a fluid-structure interaction technique is proposed to evaluate the wave-induced loads and hydroelastic responses of a single module VLFS under freak wave circumstances. The accuracy and reliability of the approach are validated through comparisons with other numerical methods. The study reveals that freak waves can cause significant increase in the global motion and vertical bending moment of VLFS, providing valuable insights for the structural design of VLFS under survival conditions.
Article
Engineering, Marine
Ningyuan Duan, Chuang Wu, Yuhong Huang, Zhenguo Zhang, Hongxing Hua
Summary: This paper investigates the active control method for reducing lateral vibration transmission in the propeller-shaft coupling system. Experimental results show the feasibility of the proposed method.
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.