Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions

Systems of ocean current power generation are generally moored deep in the seabed. The mooring system is like ropes. The ropes are very long and can provide tension but not compression, and their dynamic displacement is large and unstable, which is different from traditional structures. To generate...

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Main Authors: Shueei-Muh Lin, Wen-Rong Wang, Hsin Yuan
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Journal of Marine Science and Engineering
Subjects:
Online Access:https://www.mdpi.com/2077-1312/11/8/1533
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author Shueei-Muh Lin
Wen-Rong Wang
Hsin Yuan
author_facet Shueei-Muh Lin
Wen-Rong Wang
Hsin Yuan
author_sort Shueei-Muh Lin
collection DOAJ
description Systems of ocean current power generation are generally moored deep in the seabed. The mooring system is like ropes. The ropes are very long and can provide tension but not compression, and their dynamic displacement is large and unstable, which is different from traditional structures. To generate high-efficiency ocean current power generation, it is necessary to design a stable mooring system. Maintaining the stability and small dynamic displacement of the ocean current invertor is significantly helpful for the high efficiency of the invertor. In addition, the stability of the mooring system and a small dynamic tension, high safety factor, and long life of the mooring ropes are essential. In this study, we investigate the transient behavior of a mooring system composed of an inverter platform, pontoon, and ropes under initial conditions. An analytical method is proposed. The transient translational and rotational displacements are composed of 36 independent normalized fundamental solutions. The composition depends on the initial conditions. Each fundamental solution is derived by using the Frobenius method. This study proposes the replacement of the traditional single-rope mode with the double-rope parallel mode, which can maintain a high fracture strength and low effective spring constant in the rope. It is verified that this design can decrease instantaneous tension and increase the safety factor of the rope. Additionally, high hydrodynamic damping coefficients can significantly increase the stability of the mooring system.
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spelling doaj.art-dee39508932549baa0e0caa1954bd70f2023-11-19T01:45:23ZengMDPI AGJournal of Marine Science and Engineering2077-13122023-07-01118153310.3390/jmse11081533Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial ConditionsShueei-Muh Lin0Wen-Rong Wang1Hsin Yuan2Green Energy Technology Research Centre (GETRC), Department of Mechanical Engineering, Kun Shan University, Tainan 710, TaiwanGreen Energy Technology Research Centre (GETRC), Department of Mechanical Engineering, Kun Shan University, Tainan 710, TaiwanGreen Energy Technology Research Centre (GETRC), Department of Mechanical Engineering, Kun Shan University, Tainan 710, TaiwanSystems of ocean current power generation are generally moored deep in the seabed. The mooring system is like ropes. The ropes are very long and can provide tension but not compression, and their dynamic displacement is large and unstable, which is different from traditional structures. To generate high-efficiency ocean current power generation, it is necessary to design a stable mooring system. Maintaining the stability and small dynamic displacement of the ocean current invertor is significantly helpful for the high efficiency of the invertor. In addition, the stability of the mooring system and a small dynamic tension, high safety factor, and long life of the mooring ropes are essential. In this study, we investigate the transient behavior of a mooring system composed of an inverter platform, pontoon, and ropes under initial conditions. An analytical method is proposed. The transient translational and rotational displacements are composed of 36 independent normalized fundamental solutions. The composition depends on the initial conditions. Each fundamental solution is derived by using the Frobenius method. This study proposes the replacement of the traditional single-rope mode with the double-rope parallel mode, which can maintain a high fracture strength and low effective spring constant in the rope. It is verified that this design can decrease instantaneous tension and increase the safety factor of the rope. Additionally, high hydrodynamic damping coefficients can significantly increase the stability of the mooring system.https://www.mdpi.com/2077-1312/11/8/1533transient motioninitial conditiondouble-rope parallel modeocean currentmooring systemstability
spellingShingle Shueei-Muh Lin
Wen-Rong Wang
Hsin Yuan
Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions
Journal of Marine Science and Engineering
transient motion
initial condition
double-rope parallel mode
ocean current
mooring system
stability
title Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions
title_full Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions
title_fullStr Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions
title_full_unstemmed Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions
title_short Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions
title_sort transient translational rotational motion of an ocean current converter mooring system with initial conditions
topic transient motion
initial condition
double-rope parallel mode
ocean current
mooring system
stability
url https://www.mdpi.com/2077-1312/11/8/1533
work_keys_str_mv AT shueeimuhlin transienttranslationalrotationalmotionofanoceancurrentconvertermooringsystemwithinitialconditions
AT wenrongwang transienttranslationalrotationalmotionofanoceancurrentconvertermooringsystemwithinitialconditions
AT hsinyuan transienttranslationalrotationalmotionofanoceancurrentconvertermooringsystemwithinitialconditions