The influence of wave–current on the motion response of air-floating structure

2021 ◽  
Vol 13 (6) ◽  
pp. 063305
Author(s):  
Pengwen Wang ◽  
Haijun Wang ◽  
Yaohua Guo ◽  
Xu Yang ◽  
Fangdi Ye ◽  
...  
Keyword(s):  
Floating Structure ◽  
Motion Response

Planning and Design of Floating Offshore Architecture

2020 ◽  
Author(s):  
Akane Takahashi ◽  
Ikuo Yoshida
Keyword(s):  
Offshore Structures ◽  
Tokyo Bay ◽  
Offshore Structure ◽  
Floating Structure ◽  
Sea Levels ◽  
Motion Response ◽  
Response Characteristics ◽  
Planning And Design ◽  
Movement Characteristics ◽  
Rising Sea Levels

Abstract Floating offshore structures are attracting increasing attention as a method for addressing problems such as rising sea levels due to global warming and the increasing global populations. However, unlike ground structures, floating offshore structures must consider the effects of waves. The movement characteristics of the floating offshore structure have been reported. However, no studies have compared variations in motion response characteristics according to the scale of floating structures or buildings atop them, so it is currently difficult during the initial planning and design stages to estimate the size of superstructures that can be designed for a given marine area. Therefore, with the aim of obtaining basic data for planning floating offshore structures, in this study we developed floating structure modules (a square 36m on a side) according to their superstructure and investigated the basic motion response characteristics for each. We furthermore derived tendencies for horizontal acceleration and inclination occurring in individual modules according to design waves for Tokyo Bay.

An Analytical Approach to Modeling of Motion-Response of Floating Structure for Ocean Renewable Energy Conversion System

2018 ◽  
Vol 874 ◽  
pp. 44-49
Author(s):  
Sony Junianto ◽  
Rudi Walujo Prastianto ◽  
Mukhtasor
Keyword(s):  
Renewable Energy ◽  
Energy Conversion ◽  
Ocean Energy ◽  
Floating Structure ◽  
Motion Response ◽  
Ocean Renewable Energy ◽  
Lagrange Formula ◽  
Conversion System ◽  
Energy Conversion System ◽  
The Stability

Ocean renewable energy research has been progressing well. Supporting structures are needed to convert energy from the sea. This paper discusses the response of the floating structure for ocean renewable energy conversion system by providing a simple design of floating structure. Due to its function, the system is limited for the pitching motion. By using the Lagrange formula, the equation of motion of the system can be obtained. In the analysis, there are three variations of wave period to determine the response of floating structure motion. The result shows the trend where the larger wave periods induce larger intersection angle (larger response) of the structure. The floating structure configuration for the ocean energy converter should be determined in such a way that have the most stable motion-response in any condition. The stability of floating structure will affect the current forces in the rotated turbine. It needs a specific design to hold the stability of floating structure.

Motion response of round shape FLNG due to interaction with another floating structure

2016 ◽  
pp. 317-324
Author(s):  
J Koto ◽  
C Siow ◽  
C Soares ◽  
H Yasukawa ◽  
A Matsuda ◽  
...  
Keyword(s):  
Floating Structure ◽  
Motion Response ◽  
Round Shape

scholarly journals Research on Hydroelastic Response of an FMRC Hexagon Enclosed Platform

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1110
Author(s):  
Wei-Qin Liu ◽  
Luo-Nan Xiong ◽  
Guo-Wei Zhang ◽  
Meng Yang ◽  
Wei-Guo Wu ◽  
...  
Keyword(s):  
Time Domain ◽  
Numerical Models ◽  
Structural Response ◽  
Deep Ocean ◽  
Surface Model ◽  
Large Area ◽  
Floating Structure ◽  
Small Depth ◽  
Response Amplitude Operators ◽  
Hydroelastic Response

The numerical hydroelastic method is used to study the structural response of a hexagon enclosed platform (HEP) of flexible module rigid connector (FMRC) structure that can provide life accommodation, ship berthing and marine supply for ships sailing in the deep ocean. Six trapezoidal floating structures constitute the HEP structure so that it is a symmetrical very large floating structure (VLFS). The HEP has the characteristics of large area and small depth, so its hydroelastic response is significant. Therefore, this paper studies the structural responses of a hexagon enclosed platform of FMRC structure in waves by means of a 3D potential-flow hydroelastic method based on modal superposition. Numerical models, including the hydrodynamic model, wet surface model and finite element method (FEM) model, are established, a rigid connection is simulated by many-point-contraction (MPC) and the number of wave cases is determined. The load and structural response of HEP are obtained and analyzed in all wave cases, and frequency-domain hydroelastic calculation and time-domain hydroelastic calculation are carried out. After obtaining a number of response amplitude operators (RAOs) for stress and time-domain stress histories, the mechanism of the HEP structure is compared and analyzed. This study is used to guide engineering design for enclosed-type ocean platforms.

scholarly journals Impact of Typhoons on Floating Offshore Wind Turbines: A Case Study of Typhoon Mangkhut

2021 ◽  
Vol 9 (5) ◽  
pp. 543
Author(s):  
Jiawen Li ◽  
Jingyu Bian ◽  
Yuxiang Ma ◽  
Yichen Jiang
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Safety Evaluation ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Motion Response ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Coupling Motion

A typhoon is a restrictive factor in the development of floating wind power in China. However, the influences of multistage typhoon wind and waves on offshore wind turbines have not yet been studied. Based on Typhoon Mangkhut, in this study, the characteristics of the motion response and structural loads of an offshore wind turbine are investigated during the travel process. For this purpose, a framework is established and verified for investigating the typhoon-induced effects of offshore wind turbines, including a multistage typhoon wave field and a coupled dynamic model of offshore wind turbines. On this basis, the motion response and structural loads of different stages are calculated and analyzed systematically. The results show that the maximum response does not exactly correspond to the maximum wave or wind stage. Considering only the maximum wave height or wind speed may underestimate the motion response during the traveling process of the typhoon, which has problems in guiding the anti-typhoon design of offshore wind turbines. In addition, the coupling motion between the floating foundation and turbine should be considered in the safety evaluation of the floating offshore wind turbine under typhoon conditions.

Experimental Investigation vs Numerical Simulation of the Dynamic Response of a Moored Floating Structure to Waves

2014 ◽  
Author(s):  
Daniele Dessi ◽  
Sara Siniscalchi Minna
Keyword(s):  
Dynamical Behavior ◽  
Irregular Waves ◽  
Mooring Line ◽  
Floating Structure ◽  
Mooring Lines ◽  
Wave Energy Converters ◽  
Time Histories ◽  
Actual Configuration ◽  
Proper Orthogonal ◽  
Dynamic Wave

A combined numerical/theoretical investigation of a moored floating structure response to incoming waves is presented. The floating structure consists of three bodies, equipped with fenders, joined by elastic cables. The system is also moored to the seabed with eight mooring lines. This corresponds to an actual configuration of a floating structure used as a multipurpose platform for hosting wind-turbines, aquaculture farms or wave-energy converters. The dynamic wave response is investigated with numerical simulations in regular and irregular waves, showing a good agreement with experiments in terms of time histories of pitch, heave and surge motions as well as of the mooring line forces. To highlight the dynamical behavior of this complex configuration, the proper orthogonal decomposition is used for extracting the principal modes by which the moored structure oscillates in waves giving further insights about the way waves excites the structure.

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