scholarly journals Insight of Numerical Simulation for Current Circulation on the Steep Slopes of Bathymetry and Topography in Palu Bay, Indonesia

Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 234
Author(s):  
Mohammad Lutfi
Keyword(s):  
Current Velocity ◽  
Tidal Current ◽  
Lower Layer ◽  
River Estuary ◽  
River Mouth ◽  
Middle Layer ◽  
Open Boundary ◽  
Tidal Current Velocity ◽  
Average Current ◽  
Steep Slopes

The steep slope of the bathymetry and topography that surrounds Palu Bay is a unique morphology of the area that affects the currents. A simulation was carried out in three regions with seven scenarios to understand the effect of wind, tide, and discharge on currents. The results showed that the average current pattern in Palu Bay is more dominantly influenced by tides at the open boundary and in the middle of the bay, steered by wind directions. The velocity decreases when it reaches the end of the bay and eventually reverses back to the mouth of the bay through both sides of the bay. The current in the Palu River estuary with a discharge of 36 m3/s moves out of the river mouth. On the other hand, results with a discharge of 2 m3/s revealed that the tidal current in the middle layer to the lower layer moves in the opposite direction to the current generated by the discharge in the layer above. It means that the tidal current velocity is lower than that generated by the river discharge. The computation revealed a good agreement with observed current velocity at the selected observation points.

scholarly journals ESTIMATION OF ELECTRICITY GENERATED FROM TIDAL ENERGY IN BEDONO VILLAGE OF DEMAK REGENCY

2020 ◽  
Vol 4 (9) ◽  
pp. 13-17
Author(s):  
Agus Margiantono ◽  
Titik Nurhayati ◽  
Wahib Hasbullah
Keyword(s):  
Electric Power ◽  
Current Velocity ◽  
Tidal Current ◽  
Tidal Energy ◽  
Tidal Currents ◽  
Active Power ◽  
Tidal Current Velocity ◽  
The Village

In some places in the village of Bedono Demak Regency there is a location with high tidal current velocity, the coordinates of the Location is 6 ° 55'29.0 "S 110 ° 29'11.4" E. In this study estimated the amount of electric power that can be generated from tidal currents in the village Bedono. Estimates are made by modeling the location and the Darrieus turbine using the CFD (Computating Fluid Dinamyc) Software. From the research that has been done to get the results of electric power that can be produced in the village Bedono highest at 14-16 times 3469.413W and lowest 39.002W at 22-24 hours according to the CFD is the highest active power occurred at 14-16 at 3197.064W and the lowest 35.941W at 22-24 hours.

scholarly journals A comparative study for tidal current velocity prediction using simplified and fast algorithms

2020 ◽  
Vol 104 ◽  
pp. 102346 ◽  
Author(s):  
J. Tondut ◽  
T. El Tawil ◽  
J. Thiébot ◽  
N. Guillou ◽  
M. Benaouicha
Keyword(s):  
Comparative Study ◽  
Current Velocity ◽  
Tidal Current ◽  
Fast Algorithms ◽  
Tidal Current Velocity ◽  
Velocity Prediction

A Towing Test of a Floating Type VAMT With Cycloidal Pitch-Controlled Blades

2018 ◽  
Author(s):  
Tomoki Ikoma ◽  
Hiroaki Eto ◽  
Koichi Masuda ◽  
Atsuhiro Oguchi
Keyword(s):  
Control System ◽  
Current Velocity ◽  
Tidal Current ◽  
Vertical Axis ◽  
Floating Structure ◽  
Current Generation ◽  
Variable Pitch ◽  
Pitch Control ◽  
Tidal Current Velocity ◽  
Vertical Axis Turbine

Sea areas around the Japanese Islands which is feasible for tidal current generation are not a lot because sea sites where tidal current velocity is above 2.0 m/s are a few. We can find such sea sites at a west side of the Kyushu Island especially. However, we would earn electrical energy to be generated if it is able to generate electricity long time using around 1.0 m/s in current velocity. A vertical axis turbine should be better than horizontal axis types because VATs can take relatively higher torque. It is very useful that we can set and control a marine turbine to be higher performance in various current velocity. The present study introduce variable pitch-control system to a vertical axis turbine for tidal current generation. The pitch-control system adapts a cycloidal mechanism so that to vary pitch angle of turbine blades is conducted mechanically. The study developed a vertical axis marine turbine with cycloidal pitch-controlled three blades which was based on previous studies and experimental data. The diameter of the turbine is 1.0 m, length of a blade is 1.3 m. The turbine was set on a floating structure in order to carry out towing tests at a sea. We obtained several kinds of data from the towing tests, which were turbine torque, the number of rotation of the turbine, output power from an electrical generator and acceleration of the floating structure. As a result, the turbine made 50 W power from the generator. Although the PTO was not so large, the pitch-control was effective very much. Some issues were found at the same time. We need to consider and develop more useful gears, assemble methods to be feasible of variable pitch system.

scholarly journals Comparative Investigations of Tidal Current Velocity Prediction Considering Effect of Multi-Layer Current Velocity

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6417
Author(s):  
Bo Feng ◽  
Peng Qian ◽  
Yulin Si ◽  
Xiaodong Liu ◽  
Haixiao Yang ◽  
...  
Keyword(s):  
Machine Learning ◽  
Current Velocity ◽  
Tidal Current ◽  
Learning Algorithms ◽  
Critical Role ◽  
Tidal Energy ◽  
Machine Learning Algorithms ◽  
Tidal Current Velocity ◽  
Velocity Prediction ◽  
Prediction Approach

Accurate tidal current prediction plays a critical role with increasing utilization of tidal energy. The classical prediction approach of the tidal current velocity adopts the harmonic analysis (HA) method. The performance of the HA approach is not ideal to predict the high frequency components of tidal currents due to the lack of capability processing the non-astronomic factor. Recently, machine learning algorithms have been applied to process the non-astronomic factor in the prediction of tidal current. In this paper, a tidal current velocity prediction considering the effect of the multi-layer current velocity method is proposed. The proposed method adopts three machine learning algorithms to establish the prediction models for comparative investigations, namely long-short term memory (LSTM), back-propagation (BP) neural network, and the Elman regression network. In the case study, the tidal current data collected from the real ocean environment were used to validate the proposed method. The results show that the proposed method combined with the LSTM algorithm had higher accuracy than both the commercial tidal prediction tool (UTide) and the other two algorithms. This paper presents a novel tidal current velocity prediction considering the effect of the multi-layer current velocity method, which improves the accuracy of the power flow prediction and contributes to the research in the field of tidal current velocity prediction and the capture of tidal energy.

scholarly journals Tidal current energy potential of Nalón river estuary assessment using a high precision flow model

2018 ◽  
Vol 8 (1) ◽  
pp. 118-123
Author(s):  
Nicolás Badano ◽  
Rodolfo Espina Valdés ◽  
Eduardo Álvarez Álvarez
Keyword(s):  
High Precision ◽  
Hydrodynamic Model ◽  
Tidal Current ◽  
Flow Model ◽  
River Estuary ◽  
River Mouth ◽  
Hydrodynamic Models ◽  
Energy Potential ◽  
Tidal Current Energy ◽  
Current Energy

Abstract Obtaining energy from tide currents in onshore locations is of great interest due to the proximity to the points of consumption. This opens the door to the feasibility of new installations based on hydrokinetic microturbines even in zones of moderate speed. In this context, the accuracy of energy predictions based on hydrodynamic models is of paramount importance. This research presents a high precision methodology based on a multidimensional hydrodynamic model that is used to study the energetic potential in estuaries. Moreover, it is able to estimate the flow variations caused by microturbine installations. The paper also shows the results obtained from the application of the methodology in a study of the Nalón river mouth (Asturias, Spain).

scholarly journals THREE-DIMENSIONAL SIMULATION OF TIDAL CURRENT IN LAMPUNG BAY: DIAGNOSTIC NUMERICAL EXPERIMENTS

2010 ◽  
Vol 3 (-) ◽  
Author(s):  
Alan Frendy Koropitan ◽  
Safwan Hadi ◽  
Ivonne M.Radjawane
Keyword(s):  
Tidal Current ◽  
Lower Layer ◽  
Three Dimensional ◽  
Ocean Model ◽  
Residual Current ◽  
Global Ocean ◽  
Open Boundary ◽  
Ocean Tide ◽  
Tidal Elevation ◽  
Diagnostic Mode

Princeton Ocean Model (POM) was used to calculate the tidal current in Lampung Bay using diagnostic mode. The model was forced by tidal elevation, which was given along the open boundary using a global ocean tide model-ORITIDE. The computed tidal elevation at St. 1 and St 2 are in a good agreement with the observed data, but the computed tidal current at St 1 at depth 2 m is not good and moderate approximation is showed at depth 10 m. Probably, it was influenced by non-linier effect of coastal geometry and bottom friction because of the position of current meter, mooring closed to the coastline. Generally, the calculated tidal currents in all layers show that the water flows into the bay during flood tide and goes out from the bay during ebb tide. The tidal current becomes strong when passing through the narrow passage of Pahawang Strait. The simulation of residual tidal current with particular emphasis on predominant contituent of M2 shows a strong inflow from the western part of the bay mouth, up to the central part of the bay, then the strong residual current deflects to the southeast and flows out from the eastern part of the bay mouth. This flow pattern is apparent in the upper and lower layer. The other part flows to the bay head and froms an antic lockwise circulation in the small basin region of the bay head. The anticlockwise circulations are showed in the upper layer and disappear in the layer near the bottom. Keywords: POM, diagnostic mode, tidal current, residual current, Lampung Ba.

scholarly journals On Tidal Current Velocity Vector Time Series Prediction: A Comparative Study for a French High Tidal Energy Potential Site

2019 ◽  
Vol 7 (2) ◽  
pp. 46 ◽  
Author(s):  
Tony El Tawil ◽  
Nicolas Guillou ◽  
Jean-Frédéric Charpentier ◽  
Mohamed Benbouzid
Keyword(s):  
Time Series ◽  
Numerical Model ◽  
Linear Approximation ◽  
Current Velocity ◽  
Tidal Current ◽  
Tidal Energy ◽  
Energy System ◽  
Energy Potential ◽  
Tidal Current Velocity ◽  
Tidal Stream

Estimating the energy potential of tidal stream site is a key feature for tidal energy system deployment. This paper aims to compare two methods of prediction of tidal current velocities. The first one is based on the use of a fully three-dimensional (3D) numerical approach. However, while being accurate, the numerical model is highly time-consuming. The second method is based on a linear approximation of the tidal current, which only requires preliminary knowledge of local current velocities time series during two typical tidal cycles. This second method allows a very quick evaluation of the tidal stream resource during a long time period. The proposed comparison is done in three different locations of a high potential tidal energy site in west of France. It is carried out in terms of current velocity and energy harnessing for several turbines technology options (with and without yaw). The achieved results show that the linear approximation gives satisfactory evaluation of the tidal stream potential and can be a very interesting tool for preliminary site evaluation and first technology options selection. However, the fully 3D numerical model can obviously be very useful in more advanced steps of a project.

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