scholarly journals Mooring Stability Study for Novel Wave Energy Converter Based on Regular Wave

2021 ◽  
Vol 9 (10) ◽  
pp. 1095
Author(s):  
Zhongliang Meng ◽  
Yun Chen ◽  
Yanjun Liu ◽  
Yi Ding
Keyword(s):  
Wave Energy ◽  
Field Measurements ◽  
Wave Theory ◽  
Wave Force ◽  
Vital Role ◽  
Stability Study ◽  
Mooring System ◽  
Regular Wave ◽  
The Stability ◽  
Sea Area

The mooring system not only plays a vital role in keeping wave energy generators floating stably, but also affects the success of engineering design. Combining wave force theory and the hydrological data obtained from the field measurements of a certain sea area in the Bohai Sea, the Stokes second-order wave theory was adopted to design the mooring system of a new type of power-generating device. At the same time, the study uses the Aqwa software to gather the dynamic data of a power-generating device in a real test, and then makes models and carries out regular wave tests so as to verify the viability of the mooring system and the stability of the whole power-generating device. All of this work will provide a theoretical basis for the manufacture of an engineering prototype and its reliable supply of power.

scholarly journals Mooring Angle Study of a Horizontal Rotor Wave Energy Converter

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 344
Author(s):  
Zhongliang Meng ◽  
Yanjun Liu ◽  
Jian Qin ◽  
Shumin Sun
Keyword(s):  
Wave Energy ◽  
Field Measurements ◽  
Wave Theory ◽  
Simulation Method ◽  
Vital Role ◽  
Wave Energy Converter ◽  
Mooring System ◽  
Energy Converter ◽  
Wave Statistics ◽  
Fifth Order

The horizontal rotor wave energy converter is a newly designed wave energy converter. While the mooring system plays a vital role in keeping the device floating stably, the selection of the mooring angle has immediate effects on the device’s floating stability and energy generation efficiency. Given the properties of wave energy along the coast in Shandong Province, this study combines wave statistics gathered from field measurements of a certain area in the Bohai Sea with hydrological data obtained in a field test in the same sea area and adopts Stokes’ fifth-order wave theory to theoretically design and simulate the mooring system for the new type of power generating device. With the help of AQWA software, data on the dynamics of the device at various angles are obtained to construct models and carry out regular wave experiments according to the most appropriate mooring angles to show the validity of the selected mooring angles. The consistency of the results between the experiment and simulation confirms that under the same working conditions of regular waves, as the mooring angle increases, the roll angle decreases first and then increases, the pitch angle barely varies, and the yaw angle decreases first and then increases. The adoption of this simulation method and the gathered experimental data help to provide theoretical and practical bases for choosing the mooring method for the engineering prototype and obtaining a reliable supply of power.

scholarly journals BREAKWATER ARMOR DISPLACEMENT THRESHOLDS: A POSSIBLE CORRELATION WITH CUMULATIVE WAVE ENERGY

1984 ◽  
Vol 1 (19) ◽  
pp. 186
Author(s):  
Daniel L. Behnke ◽  
Frederic Raichlen
Keyword(s):  
Wave Energy ◽  
Wave Train ◽  
Wave Length ◽  
Simple Wave ◽  
Wave Theory ◽  
Irregular Waves ◽  
Reconstruction Technique ◽  
Regular Wave ◽  
Regular Waves ◽  
Three Dimensional Model

An extensive program of stability experiments in a highly detailed three-dimensional model has recently been completed to define a reconstruction technique for a damaged breakwater (Lillevang, Raichlen, Cox, and Behnke, 1984). Tests were conducted with both regular waves and irregular waves from various directions incident upon the breakwater. In comparison of the results of the regular wave tests to those of the irregular wave tests, a relation appeared to exist between breakwater damage and the accumulated energy to which the structure had been exposed. The energy delivered per wave is defined, as an approximation, as relating to the product of H2 and L, where H is the significant height of a train of irregular waves and L is the wave length at a selected depth, calculated according to small amplitude wave theory using a wave period corresponding to the peak energy of the spectrum. As applied in regular wave testing, H is the uniform wave height and L is that associated with the period of the simple wave train. The damage in the model due to regular waves and that caused by irregular waves has been related through the use of the cumulative wave energy contained in those waves which have an energy greater than a threshold value for the breakwater.

Design and Calculation of Double Buoys Mooring System in Estuary of Yalu River

2012 ◽  
Vol 253-255 ◽  
pp. 2071-2075
Author(s):  
Guo You Shi ◽  
Jia Xuan Yang ◽  
Wei Feng Li
Keyword(s):  
Calculation Result ◽  
Meteorological Condition ◽  
Wave Force ◽  
Good Effect ◽  
Total Force ◽  
Mooring System ◽  
Wind Force ◽  
Method Of Calculation ◽  
Yalu River ◽  
Sea Area

In order to design a double buoys mooring system in the estuary of Yalu River for loading work of 40,000 tons of bulk cargo ship, the article mainly based on the practicality of the meteorological condition of this sea area and the data of the vessel as well as the national criterion, do some calculations of wind force, current force, wave force as well as the total force on the ship, with the calculation result to make a designation of double mooring buoy system, decide the size of the mooring buoy, the size and length of the chain, the size and the depth of the Deadman. The construction according to the designation has a good effect; the method of calculation and the designation are proved useful.

A Decade of Wave Power Development in India—The Challenges

2002 ◽  
Vol 36 (4) ◽  
pp. 59-73 ◽  
Author(s):  
S. Neelamani
Keyword(s):  
Power Plant ◽  
Wave Energy ◽  
Research Effort ◽  
Wave Force ◽  
Wave Power ◽  
Nicobar Island ◽  
Model Studies ◽  
Pilot Wave ◽  
Kerala State ◽  
The Stability

Wave energy research in India started in 1984. Six years of research by the Indian wave energy group culminated in the installation of a 150 kW capacity pilot wave power plant in Vizhinjam, off Trivandrum in the Kerala state, in the Arabian Sea during 1990 (Figure 1). The problems encountered during the research, construction and installation directed the group to continue the research effort. The structural configuration of the caisson has changed considerably so that it has sufficient floating stability during towing, enough space for sand ballasting to increase the stability of the caisson against horizontal sliding and overturning and sufficient space at the rear of the caisson for berthing vessels (Figures 2 and 3). After the installation of a wave power caisson of 150 kW off Trivandrum, further attention was focused on a 1 to 2 MW wave power plant for sites, where new breakwaters for harbors is envisaged (Thangassery Harbour in the West Coast of India (Figure 4) and Mus Bay in Car Nicobar Islands (Figure 5) in Bay of Bengal). Optimum center to center spacing between the caissons was determined based on physical model studies. Further research was carried out to improve the wave to pneumatic efficiency by changing the harbor configuration. Techniques to reduce the wave force on the caisson were also simultaneously studied. The wave power economics is site specific. Two sites (Thangassery in Kerala and Mus bay in Car Nicobar Island) were selected to analyze the wave power economics. Wave power is not likely to become economical in the near future. A continued research effort in the research is very important in order to improve the efficiency of wave power conversion and reduce the cost of construction. A decade of experience (1986 to 1996) in wave power research is presented in this paper.

Analysis of Hydrodynamic Model of Wave Energy Converter of Inverse Pendulum

2013 ◽  
Vol 483 ◽  
pp. 223-228
Author(s):  
Shou Qi Cao ◽  
Shu Man Fu ◽  
Zi Yue Wu
Keyword(s):  
Wave Energy ◽  
Hydrodynamic Model ◽  
Mechanical Energy ◽  
Wave Force ◽  
Wave Energy Converter ◽  
Energy Converter ◽  
Wave Condition ◽  
Conversion Model ◽  
Fluent Software ◽  
Sea Area

The efficiency analysis of wave energy collection and conversion is crucial for utility of wave energy of inverse pendulum. In the paper, we build the hydrodynamic model of interaction between pendulum and wave in wave energy converter of inverse pendulum. On the basis of this typical model, we choose the actual wave condition of some sea area in the east of China as the background, research the hydrodynamic property of pendulum by numerical simulation with fluent software, get the relation curve of between the rotation angle of pendulum and moment of wave force with time, and acquire energy conversion model from wave energy to mechanical energy in wave energy converter of inverse pendulum. It makes the beneficial exploration for optimal design of wave energy converter of inverse pendulum.

Oscillating Wave Surge Converter-Type Attachment for Extracting Wave Energy While Reducing Hydroelastic Responses of Very Large Floating Structures

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
H. P. Nguyen ◽  
C. M. Wang
Keyword(s):  
Wave Energy ◽  
Wave Force ◽  
Mooring System ◽  
Energy Converter ◽  
Floating Structure ◽  
Incident Wavelength ◽  
Floating Structures ◽  
Horizontal Wave ◽  
Horizontal Wave Force ◽  
Better Than

Abstract This paper presents an oscillating wave surge converter (OWSC)-type attachment, comprising a submerged vertical flap connected to the fore edge of a very large floating structure (VLFS) with hinges and linear power take-off (PTO) systems, for extracting wave energy while reducing hydroelastic responses of VLFS. In terms of reductions in hydroelastic responses of VLFS, the OWSC-type attachment is better than the recently proposed raft wave energy converter (WEC)-type attachment for relatively short waves (T < 7 s) and better than the conventional anti-motion device comprising a submerged vertical flap rigidly connected to the fore edge of VLFS for all wave periods. Importantly, the horizontal wave force acting on the submerged flap for the OWSC-type attachment is smaller than that for the conventional anti-motion device, leading to a more economical mooring system. In terms of wave energy extraction, the OWSC-type attachment is better than the raft WEC-type attachment for intermediate and long waves (T ≥ 7 s). In addition, for maximizing power production, the required flap length for the OWSC-type attachment is much smaller than the required pontoon length for the raft WEC-type attachment (about λ/10 as compared to about λ/3, where λ is the incident wavelength).

Hydrodynamic Response of Wave Energy Converters under Complex Sea State

2014 ◽  
Vol 501-504 ◽  
pp. 1919-1926
Author(s):  
Long Fei Yu ◽  
Liang Sheng Zhu
Keyword(s):  
Wave Energy ◽  
Mechanical Response ◽  
Wave Theory ◽  
Cylindrical Wave ◽  
Practical Significance ◽  
Mooring System ◽  
Ocean Energy ◽  
Sea State ◽  
Energy Devices ◽  
Wave Energy Converters

In real sea state, Ocean energy devices to work hard to stabilize, or even destroyed. Based on Airy wave theory, Movement and force of heaving cylindrical wave-energy converter (WEC) was analyzed under the complex marine state. Then setting the South China coast as the environmental background, and simulating and computing the motion response of the buoy and the mooring system under various sea conditions. The computational data show that complex mechanical response was happened and the mooring system (SM) has excellent mooring performance. The research results have practical significance for heaving cylindrical WEC survival design under real sea conditions.

Time-Domain Analysis of SOFAR Propagation in Low-Latitude Sea Area by Wave Theory and Ray Theory

1995 ◽  
Vol 34 (Part 1, No. 5B) ◽  
pp. 2940-2942
Author(s):  
Shinichi Imayoshi ◽  
Toshio Tsuchiya ◽  
Toshiaki Kikuchi ◽  
Akio Hasegawa
Keyword(s):  
Time Domain ◽  
Wave Theory ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Ray Theory ◽  
Low Latitude ◽  
Sea Area

scholarly journals Field measurements from contrasting reefs show spurs and grooves can dissipate more wave energy than the reef crest

2021 ◽  
Author(s):  
Stephanie Jane Duce ◽  
Ana Vila-Concejo ◽  
Robert Jak McCarroll ◽  
Bevan Yiu ◽  
Lachlan A Perris ◽  
...  
Keyword(s):  
Wave Energy ◽  
Field Measurements ◽  
Reef Crest

scholarly journals Viral-Mediated mRNA Degradation for Pathogenesis

Biomedicines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 111
Author(s):  
Shujuan Du ◽  
Xiaoqing Liu ◽  
Qiliang Cai
Keyword(s):  
Gene Expression ◽  
Current Knowledge ◽  
Immune Surveillance ◽  
Viral Gene Expression ◽  
Mrna Degradation ◽  
Vital Role ◽  
Viral Gene ◽  
Antiviral Immune Response ◽  
Successful Infection ◽  
The Stability

Cellular RNA decay machinery plays a vital role in regulating gene expression by altering the stability of mRNAs in response to external stresses, including viral infection. In the primary infection, viruses often conquer the host cell’s antiviral immune response by controlling the inherently cellular mRNA degradation machinery to facilitate viral gene expression and establish a successful infection. This review summarizes the current knowledge about the diverse strategies of viral-mediated regulatory RNA shutoff for pathogenesis, and particularly sheds a light on the mechanisms that viruses evolve to elude immune surveillance during infection.

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