Article
Engineering, Marine
Ravindra B. Kudupudi, Ranadev Datta, C. G. Soares
Summary: A 3D coupled method is used to model green water and study its effects on ship deck. Global vessel motions are obtained using impulse response function, while local hydrodynamic forces are computed using CFD solver and Volume of Fluid method. Results show that peak pressure due to green water increases with vessel speed but decreases with the increase of bow rake angle.
Article
Engineering, Marine
Bachar Mallat, Gregory Germain, Jean-Yves Billard, Celine Gabillet
Summary: This paper investigates the acoustic disturbances generated by the bubble sweep-down phenomenon around oceanographic research vessels. A ship model on a 1/30 scale is used in a wave and current circulating flume tank, and an optical probe is employed to measure the size and velocity of the bubbles. The results show that the optical probe method provides the advantage of knowing the bubble position in three-dimensional space.
Article
Engineering, Marine
Songxing Huang, Jialong Jiao, Chaohe Chen
Summary: This paper analyzes the motion responses of a S175 container ship hull in cross sea using numerical methods, revealing that the ship's vertical motion responses induced by cross waves can be significant and experience obvious roll-pitch-coupled motion, with severe bow slamming and green water observed. The study provides new insights for further understanding the navigation safety of ships in cross sea conditions.
JOURNAL OF MARINE SCIENCE AND TECHNOLOGY
(2022)
Review
Energy & Fuels
Andreas von Dollen, YoungSeok Hwang, Stephan Schlueter
Summary: Green hydrogen is seen as a promising alternative energy source, but building production capacities involves significant carbon emissions and fluctuations in financial and resource demands. Therefore, using alternative technologies such as turquoise hydrogen or carbon capture and storage is necessary to address these challenges.
Article
Engineering, Marine
Haoran Zhang, Wenyong Tang, Yuchao Yuan, Hongxiang Xue, Hao Qin
Summary: In this study, the impact of freak waves on ship models was investigated using numerical methods. It was found that the height and period of freak waves have significant effects on the impact on ships, with short-period freak waves causing more severe impacts.
Article
Engineering, Marine
Peter H. -Y. Lo
Summary: An approximate ship wake solution has been proposed and validated for accurately predicting both wake patterns and amplitudes in any water depth, reducing computational effort and removing singularities. Validation was done using 37 satellite images, a towing tank experiment, and two field experiments, with discussion on the effects of water depth on wake patterns. The new solution provides a potentially powerful tool for studying ship wake inversion by quickly relating ship shape, weight, speed, and water depth to wake characteristics.
Article
Engineering, Marine
Hang Xie, Xiangli Dai, Huilong Ren, Fang Liu
Summary: This paper clarifies the asymmetrical slamming load characteristics of a truncated ship bow under the combination of heel and pitch postures through drop experiment. The study provides a complete dataset and analyzes the load characteristics of bow impact under asymmetrical water entry attitudes. The results show the influence of heel and pitch angles on impact pressure and discuss load characteristics with different water entry velocities to improve its application.
Article
Engineering, Marine
Cenk Sakar, Muge Buber, Burak Koseoglu, Ali C. Toz
Summary: Confined spaces pose significant risks to workers, and risk assessment is crucial for the safety of seafarers. This research utilizes a fuzzy based bow-tie methodology to analyze the risks associated with confined spaces on-board, finding that commercial/time pressure has the highest impact. The study suggests macro-level revisions to industry practices, organizational culture, and roles and responsibilities to minimize the potential of recurrence.
Article
Engineering, Ocean
Pierre-Yves Wuillaume
Summary: This study presents the computation process of the finite depth Green function at zero forward speed based on Newman's method. The Green function is evaluated using either a series expression or an integral expression. An asymptotic analysis of the integral expression enables an accurate power series approximation over the entire range of wave frequencies. The limits of the Green function at zero and infinite frequencies are studied and found to match their expected values, demonstrating consistency with previous literature. The computation of the finite depth Green function is verified with two test cases.
APPLIED OCEAN RESEARCH
(2022)
Article
Engineering, Marine
Mehmet Kaptan
Summary: Accidents in the maritime sector, such as deaths, injuries, environmental pollution, or material damage, are common despite safety measures. This study analyzed errors in anchor handling operations using the fuzzy bow-tie method, providing insights for maritime experts to reduce risks and enhance safety.
Article
Astronomy & Astrophysics
Samuel Barroso Bellido, Fabian Wagner
Summary: In this article, a conceptual issue of the Third Quantization formalism for Canonical Quantum Gravity is pointed out. The theory and the picture of noninteracting universe-antiuniverse pairs are incomplete, based on previous results on interuniversal entanglement. It is proposed to solve the problem by adding a new quantum field to the formalism, which mediates interactions between universes and may provide a heat bath in the background.
Article
Engineering, Marine
Yifan Zhang, Xuhui Li, Shan Ma, Wenbo Shao, Yunxing Zhang
Summary: This paper introduces a numerical model that can simulate water entry of complex objects and validates the model through experiments. By simulating different bulbous bow shapes, the influence of bulbous bow shape on hydrodynamic forces is analyzed, and recommendations for choosing bulbous bow shape are provided.
Article
Engineering, Marine
Abhishek Acharya, Ranadev Datta
Summary: This study conducts a systematic parametric study to investigate the influence of various physical and geometrical parameters on bow slamming load, and develops an empirical formula for quick prediction of bow slamming pressure.
Article
Automation & Control Systems
Liping Liu, Bo Lian, Changgeng Zhou, Kehao Duan, Xueming Zhu, Pingfeng Xia
Summary: Choosing tools with appropriate geometric structure is crucial in preventing delamination during drilling CFRP, and the plane rake-faced twist drill demonstrates better performance in this regard, with good inhibition effects at the entrance and exit.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Engineering, Marine
Hang Xie, Xuefeng Wei, Fang Liu, Huilong Ren, Xinyu Liu, Zhongfei Chen
Summary: This paper proposes an experimental study to isolate the impact characteristics of water entry of a 3D bow-flare model with various pitch angles. The results show that the pitch angle greatly increases the slamming pressure in the flare region, providing insights into 3D water entry with various pitch angles that will be helpful for the structural design of ships.
