scholarly journals Kinerja Model Fisik Konverter Energi Ombak Rangkaian Gear Searah pada Periode Ombak yang Bervariasi

2016 ◽  
Vol 22 (2) ◽  
pp. 71 ◽  
Author(s):  
Masjono Muchtar ◽  
Salama Manjang ◽  
Dadang A Suriamiharja ◽  
M Arsyad Thaha

To date there were few research on the effect of non-linearity properties of the ocean waves on the performance of wave energy converter (WEC), which uses a series of unidirectional gear. One such parameter is the variation of wave period. The influence of wave period variations on the performance of physical model of the wave energy converters have been investigated at the Hydraulics Laboratory, Department of Civil Engineering, Hasanuddin University Indonesia. This WEC physical model was fabricated and assembled at Politeknik ATI Makassar Indonesia. The investigation steps consists of physical model development, physical model investigation at wave flume prior to the wave period  variation, measuring input output parameters of the physical model under test and empirical model formulation based on observed data analysis. Physical model test carried out on the wave flume at the Hydraulics Laboratory of the Department of Civil Hasanuddin University, at a water depth of 25 cm, wave height between 5-9 cm and wave period between 1.2 - 2.2 seconds. Investigation result based on flywheel radial speed (RPM) and torque (Nm) indicated that calculated harvested power was inversely proportional with the wave period. The longer the period of the waves, the energy produced is getting smaller. The derived empirical formula was y = -85.598x + 208.53 and R² = 0.8881. Y is energy produced (Watt) and X is the wave period (Second). Formulations generated from this study could be used as a reference for future research in dealing with wave period variations on a design one way gear wave energy converter as a source of renewable energy.

2021 ◽  
Vol 8 ◽  
Author(s):  
Dongsheng Qiao ◽  
Guangning Zhi ◽  
Haizhi Liang ◽  
Dezhi Ning ◽  
Jun Yan ◽  
...  

The physical model test interlinks the concept design and sea trial during the commercial utilization of wave energy converter. Aiming at the oscillating buoy wave energy converter, the energy conversion principle is firstly decomposed. Then, the model scale requirement of fluid motion and corresponding hydrodynamic similarity criterion considered in the physical model test are introduced. Finally, the solution of scaling orchestration problem is proposed considering the overall model scale in different energy conversion processes. The hydrodynamic similarity criterion is selected based on the working mechanism of the energy-capturing body only in contact with water, and the model scale requirements during the other stages of energy conversion structure are determined by the main mechanical factors. The first-stage energy conversion of device is recommended to meet the Froude similarity requirements, while the second-stage and third-stage energy conversions only need to meet the power similarity requirements. The power scale ratio in the three energy conversions is recommended to be consistent with the Froude similarity, and there are no requirements of geometric shape of second-stage and third-stage energy conversions to meet the similarity criteria.


2011 ◽  
Vol 1 (32) ◽  
pp. 64 ◽  
Author(s):  
Hernan Fernandez ◽  
Gregorio Iglesias ◽  
Rodrigo Carballo ◽  
Alberte Castro ◽  
Pedro Bartolomé

Wave energy presents a great potential in many coastal regions. This paper deals with WaveCat©, a new Wave Energy Converter (WEC) recently patented by the University of Santiago de Compostela. First, the WaveCat© concept and its main design elements. It is a floating WEC intended for intermediate water depths (50–75 m), whose principle of energy capture is wave overtopping. WaveCat© consists of two hulls, like a catamaran (hence its name); however, unlike a catamaran, the hulls are convergent so as to leave a wedge between them. Waves propagate into this wedge and, eventually, overtop the inner hull sides. Overtopping water is collected in onboard tanks and, subsequently, drained back to sea, propelling ultra-low head turbines in the process. The wave flume tests carried out on a 3D, fixed model at a 1:67 scale are presented. Development work is ongoing, including a numerical model—which is currently being validated based on the results from the physical model—and a 3D, floating physical model at a larger scale (1:30).


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1997 ◽  
Author(s):  
Tunde Aderinto ◽  
Hua Li

Different concepts and methods have been proposed and developed by many researchers to harvest ocean wave energy. In this paper, a new self-adjustable wave energy converter concept is presented, which changes its inertia through ballasting and de-ballasting using sea water. The trigger of ballasting and de-ballasting is controlled by the critical wave period. Therefore, the self-adjustable wave energy converter is able to interact at resonance with the ocean waves at two different resonant bandwidths. Ten years real wave data with hourly resolution from a selected location in Gulf of Mexico was used in this paper to decide the critical wave period and other parameters of the wave energy converter. The annual energy performance of the self-adjustable wave energy converter was also estimated and compared with non-adjustable wave energy converter with similar dimensions. Structural analysis including both static and fatigue analysis was performed on the self-adjustable wave energy converter to determine its survivability with the real ocean wave data. The results show that the self-adjustable wave energy converter is able to capture more energy than non-adjustable wave energy converter, and is able to survive during the hash ocean wave conditions.


2021 ◽  
Vol 9 (3) ◽  
pp. 309
Author(s):  
James Allen ◽  
Gregorio Iglesias ◽  
Deborah Greaves ◽  
Jon Miles

The WaveCat is a moored Wave Energy Converter design which uses wave overtopping discharge into a variable v-shaped hull, to generate electricity through low head turbines. Physical model tests of WaveCat WEC were carried out to determine the device reflection, transmission, absorption and capture coefficients based on selected wave conditions. The model scale was 1:30, with hulls of 3 m in length, 0.4 m in height and a freeboard of 0.2 m. Wave gauges monitored the surface elevation at discrete points around the experimental area, and level sensors and flowmeters recorded the amount of water captured and released by the model. Random waves of significant wave height between 0.03 m and 0.12 m and peak wave periods of 0.91 s to 2.37 s at model scale were tested. The wedge angle of the device was set to 60°. A reflection analysis was carried out using a revised three probe method and spectral analysis of the surface elevation to determine the incident, reflected and transmitted energy. The results show that the reflection coefficient is highest (0.79) at low significant wave height and low peak wave period, the transmission coefficient is highest (0.98) at low significant wave height and high peak wave period, and absorption coefficient is highest (0.78) when significant wave height is high and peak wave period is low. The model also shows the highest Capture Width Ratio (0.015) at wavelengths on the order of model length. The results have particular implications for wave energy conversion prediction potential using this design of device.


Author(s):  
Seyed Milad Mousavi ◽  
Majid Ghasemi ◽  
Mahsa Dehghan Manshadi ◽  
Amir Mosavi

Accurate forecasts of ocean waves energy can not only reduce costs for investment but it is also essential for management and operation of electrical power. This paper presents an innovative approach based on the Long Short Term Memory (LSTM) to predict the power generation of an economical wave energy converter named “Searaser”. The data for analyzing is provided by collecting the experimental data from another study and the exerted data from numerical simulation of searaser. The simulation is done with Flow-3D software which has high capability in analyzing the fluid solid interactions. The lack of relation between wind speed and output power in previous studies needs to be investigated in this field. Therefore, in this study the wind speed and output power are related with a LSTM method. Moreover, it can be inferred that the LSTM Network is able to predict power in terms of height more accurately and faster than the numerical solution in a field of predicting. The network output figures show a great agreement and the root mean square is 0.49 in the mean value related to the accuracy of LSTM method. Furthermore, the mathematical relation between the generated power and wave height was introduced by curve fitting of the power function to the result of LSTM method.


Author(s):  
Ken Rhinefrank ◽  
Al Schacher ◽  
Joe Prudell ◽  
Erik Hammagren ◽  
Zhe Zhang ◽  
...  

This paper presents a novel 1:7 scale point absorber wave energy converter (WEC), developed by Columbia Power Technologies (COLUMBIA POWER). Four hydrodynamic modeling tools were employed in the scaled development and the optimization process of the WEC, including WAMIT, Garrad Hassan’s GH WaveFarmer, OrcaFlex and ANSYS AQWA. The numerical analysis development is discussed, and the performance and mooring estimates at 1:7 scale and full scale are evaluated and optimized. The paper includes the development of the 1:7 scale physical model and the associated WEC field testing in Puget Sound, WA.


Author(s):  
Chris Sharp ◽  
Bryony DuPont

For consumers residing near a coastline, and especially for those living or working in remote coastal areas, ocean energy is a promising source of electricity that has the potential to serve as a primary energy source. Over the last decade, many wave energy converter (WEC) designs have been developed for extracting energy from the ocean waves, and with the progression of these devices’ ocean deployment, the industry is looking ahead to the integration of arrays of devices into the grid. Due to the many factors that can potentially influence the configuration of an array (such as device interaction and system cost) optimal positioning of WECs in an array has yet to be well understood. This paper presents the results of a novel real-coded genetic algorithm created to determine ideal array configurations in a non-discretized space such that both power and cost are included in the objective. Power is calculated such that the wave interactions between devices are considered and cost is calculated using an analytical model derived from Sandia National Laboratory’s Reference Model Project. The resulting layouts are compared against previous array optimization results, using the same constraints as previous work to facilitate algorithm comparison. With the development of an algorithm that dictates device placement in a continuous space so that optimal array configurations are achieved, the results presented in this paper demonstrate progression towards an open-source method that the wave energy industry can use to more efficiently extract energy from the ocean’s vast supply through the creation of array designs that consider the many elements of a WEC array.


2017 ◽  
Vol 24 (s3) ◽  
pp. 49-57 ◽  
Author(s):  
Ming Liu ◽  
Hengxu Liu ◽  
Xiongbo Zheng ◽  
Hailong Chen ◽  
Liquan Wang ◽  
...  

Abstract The wave energy, as a clean and non-pollution renewable energy sources, has become a hot research topic at home and abroad and is likely to become a new industry in the future. In this article, to effectively extract and maximize the energy from ocean waves, a vertical axisymmetric wave energy converter (WEC) was presented according to investigating of the advantages and disadvantages of the current WEC. The linear and quadratic equations in frequency-domain for the reactive controlled single-point converter property under regular waves condition are proposed for an efficient power take-off (PTO). A method of damping coefficients, theoretical added mass and exciting force are calculated with the analytical method which is in use of the series expansion of eigen functions. The loads of optimal reactive and resistive, the amplitudes of corresponding oscillation, and the width ratios of energy capture are determined approximately and discussed in numerical results.


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