Influence of GM on Surf-Riding and Broaching of the Fishing Vessel

Author(s):  
Liwei Yu ◽  
Ning Ma ◽  
Shuqing Wang ◽  
Tinghao Wang
Keyword(s):  
Author(s):  
Maxime Thys ◽  
Odd Magnus Faltinsen

Hydrodynamic aspects of a modern fishing vessel during manoeuvring in a seaway was studied theoretically and experimentally. The focus was on small frequencies of encounter, corresponding to following and stern quartering seas, where fishing vessels are susceptible to capsize. The numerical model was based on de Kat and Paulling [1]. The model combined a 6 degrees of freedom (DOF) blended seakeeping model with a 4 DOF non-linear manoeuvring model. The 3D non-linear Froude-Krylov and restoring loads were computed by pressure integration up to the incident free surface. The added mass, damping and wave diffraction loads were obtained by generalizing the STF (Salvesen et al. [2]) strip theory to partly include 3D flow effects by means of WAMIT. The simulated wave-induced surge forces over-estimated the experimentally measured forces by up to 50%. Excessive wave-induced surge forces led to predictions of broaching and surf riding, which did not occur in the experiments. Use of experimentally determined wave-induced surge forces gave good agreement between simulations and experiments.


2019 ◽  
Vol 31 (4) ◽  
pp. 205-236
Author(s):  
Myeong -Kyu Lee ◽  
Koji Yoshimoto

2021 ◽  
Vol 13 (11) ◽  
pp. 5858
Author(s):  
Kyumin Kim ◽  
Do-Hoon Kim ◽  
Yeonghye Kim

Recent studies demonstrate that fisheries are massive contributors to global greenhouse gas (GHG) emissions. The average Korean fishing vessel is old, fuel-inefficient, and creates a large volume of emissions. Yet, there is little research on how to address the GHG emissions in Korean fisheries. This study estimated the change in GHG emissions and emission costs at different levels of fishing operations using a steady-state bioeconomic model based on the case of the Anchovy Tow Net Fishery (ATNF) and the Large Purse Seine Fishery (LPSF). We conclude that reducing the fishing efforts of the ATNF and LPSF by 37% and 8% respectively would not only eliminate negative externalities on the anchovy and mackerel stock respectively, but also mitigate emissions and emission costs in the fishing industry. To limit emissions, we propose that the Korean government reduce fishing efforts through a vessel-buyback program and set an annual catch limit. Alternatively, the government should provide loans for modernizing old fishing vessels or a subsidy for installing emission abatement equipment to reduce the excessive emissions from Korean fisheries.


2021 ◽  
Vol 187 ◽  
pp. 116565
Author(s):  
Xinli Wang ◽  
Lei Wang ◽  
Yajie Song ◽  
Jie Deng ◽  
Youjie Zhan

1996 ◽  
Vol 40 (04) ◽  
pp. 326-336
Author(s):  
K. J. Spyrou

In earlier studies we have analyzed the phenomena which can generate loss of ship controllability in astern seas. In this paper we examine how the yaw instability associated with broaching can lead to roll instability and ship capsize. The dynamic effects responsible for capsize during the forced turn of broaching do not have their origin in the customary roll equation but are the result of interactions with other motions of the ship. Stability studies based solely on the roll equation are thus clearly inappropriate for this case where a multidimensional approach is deemed necessary. After presenting the theoretical background we set out a multi-degree method of global analysis which is based on transient maps. We apply this method to clarify how capsize occurs during the escape from surf-riding and also during transients from arbitrary initial condition of the ship. Our study establishes the connection between speed, heading, automatic control parameters and capsize. The proposed method can be useful in the context of a design methodology for minimizing the risk of ship capsize in astern seas.


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