scholarly journals Hydro-Oceanographic and Bathymetric Survey in Tanjung Merah as a Basis for Modelling Coastal Spatial Plans of Bitung City

2021 ◽  
Vol 328 ◽  
pp. 08006
Author(s):  
Joyce C Kumaat ◽  
Kalvin S Andaria ◽  
Denny Maliangkay
Keyword(s):  
Tidal Current ◽  
Mixed Type ◽  
Field Survey ◽  
Tidal Currents ◽  
Survey Method ◽  
Accurate Data ◽  
Bathymetric Survey ◽  
Tidal Current Velocity ◽  
Tidal Harmonic ◽  
Dominant Direction

The purpose of this study was to examine the parameters of Hydro-Oceanography (Tidal and Tidal Currents) and Bathymetry (Sea Depth) in Tanjung Merah, Bitung City. The method used in this research is a field survey method. The survey was carried out at the research location, precisely in Tanjung Merah, Matuari District, Bitung City. Equipment such as GPS Fish Finder, Floater Current Meter, Tidal Pole and Boats are supporting devices in obtaining accurate data on tides, tidal currents, and bathymetry in the waters of Tanjung Merah. The results showed that the tidal current conditions at the study site with several variations in the depth of the tidal current velocity ranged from 0.2 – 0.3 cm/sec with the dominant direction of the current towards the south. While the tides using tidal harmonic analysis for 15 days of observation, the Formzal Index is 0.93 which means that the tides in this location are mixed type with a single daily trend. Bathymetric conditions in Tanjung Merah identified the topography of the bottom of the waters is steep with depth variations between 2 -30 meters along the coast of Tanjung Merah while shallow areas are found at the mouth of the Tanjung Merah river.

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 COMPARISON OF TIDAL CURRENTS UNDER DIFFERENT NOURISHMENT SCHEMES ON WEST BEACH OF BEIDAIHE, CHINA

2011 ◽  
Vol 1 (32) ◽  
pp. 32 ◽  
Author(s):  
Yu Zhang ◽  
Cuiping Kuang ◽  
Lulu He ◽  
Yi Pan ◽  
Yanxiong Yang ◽  
...  
Keyword(s):  
Numerical Model ◽  
Shallow Water Equations ◽  
Tidal Current ◽  
Unstructured Grid ◽  
Field Survey ◽  
Tidal Level ◽  
Current Field ◽  
Primary Analysis ◽  
Project Area ◽  
Tidal Current Velocity

This paper detailed a study on the tidal current field around a beach nourishment project including submerged breakwaters and jetties. The effect of different nearshore structure arrangements on the tidal current field was studied utilizing a numerical model build based on the solution of two-dimensional shallow water equations and an unstructured grid. In order to calibrate the numerical model, field survey was conducted at 5 current stations and a tidal level station around the project area. According to a primary analysis on stability, environment, sight of the beach, and construction quantity, four project schemes were chosen and simulated. After comparing the modeling results, the effects of submerged breakwaters and jetties were discussed. Conclusively, it is feasible to protect the filled sand on west beach by jetties and submerged breakwaters through obvious tidal current velocity reduction in the nearshore area.

scholarly journals Research on the Blade Motion of a Bidirectional Energy-Generating Turbine under Integrated Wave and Tidal Current Action

2021 ◽  
Vol 9 (8) ◽  
pp. 869
Author(s):  
Ya-Mei Li ◽  
Ze-Yu Li ◽  
An-Dong Liu ◽  
Yu-Tian Zhu ◽  
Shi-Ming Wang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Tidal Current ◽  
Flow Direction ◽  
Time Series Prediction ◽  
Tidal Currents ◽  
Current Data ◽  
Wave Direction ◽  
Tidal Current Energy ◽  
Sea Trial ◽  
Tidal Current Velocity

An integrated wave-tidal current power turbine is affected by both wave and tidal current forces, and its energy efficiency is closely related to the velocity and direction of the two forces. To improve the probability of the horizontal axis turbine reaching maximum energy efficiency under real-time changing sea conditions, we performed the following investigations in this study. Based on the actual application scenario of Lianyungang port, a time series prediction model of tidal current (velocity and flow direction) and wave (mean wave direction, mean wave period, and significant wave height) data for the past year was established. The changes in waves and tidal currents within 24 h after the cutoff point of the existing data were predicted. The integrated wave-tidal current mechanism was studied, and the superposition of wave energy and tidal current energy was transformed into the equivalent velocity vector of wave-tidal current integration. The conversion coefficient between waves and equivalent flows was determined by a numerical wave flume simulation. According to the historical wave and tidal current data, the equivalent velocity range of the integrated action of waves and tidal currents in Lianyungang was determined. The influence of different blade motions on the energy harvesting efficiency of the turbine under the corresponding flow conditions was studied using the Computational Fluid Dynamics (CFD) method to determine the blade motion law of the turbine. The blade motion law of the prototype was verified in a sea trial experiment. The experimental results were basically consistent with the simulation results for the blade motion law designed according to the wave and tidal current prediction law. This design scheme can provide a reference for engineering design for the development and utilization of new marine energy.

Systematic Coastal Field Survey Method and Coastal Structures Management Status in the Korean Coast

2018 ◽  
Vol 85 ◽  
pp. 1461-1465
Author(s):  
Hyeong Min Oh ◽  
Soon Mi Hwang ◽  
Soo Min Kim ◽  
Tae Soon Kang ◽  
Kwang Young Jeong
Keyword(s):  
Field Survey ◽  
Survey Method ◽  
Coastal Structures

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

Behavior of Adult American Shad (Alosa sapidissima) Homing to the Connecticut River from Long Island Sound

1973 ◽  
Vol 30 (12) ◽  
pp. 1847-1860 ◽  
Author(s):  
Julian J. Dodson ◽  
William C. Leggett
Keyword(s):  
Tidal Current ◽  
Open Water ◽  
American Shad ◽  
Behavior Patterns ◽  
Connecticut River ◽  
Directed Movement ◽  
Alosa Sapidissima ◽  
Preferred Direction ◽  
Tidal Current Velocity ◽  
Ultrasonic Tracking

The migratory behavior of American shad (Alosa sapidissima) approaching their natal river during the final saltwater stage of the spawning migration was studied using ultrasonic tracking and conventional tagging procedures. Initial displacement of most sonic-tagged shad released without displacement adjacent to and 10 km west of the Connecticut River was not in the direction of the home river. These fish, however, homed successfully to the Connecticut River as did dart-tagged shad released in the same areas.Shad exhibited two major behavior patterns; countercurrent orientation in response to the reversing tidal current and adjustment of swimming speed to changes in tidal velocity. Countercurrent orientation was equally significant during daylight and darkness, whereas the adjustment of swimming speeds to tidal current velocity was more significant during daylight than darkness.Shad tracked to the west exhibited a westerly bias inherent in the basic open water behavior patterns. Shad exhibited a greater degree of directed movement when oriented against the ebb tide and adjusted their swimming speeds to exceed the ebb tide velocity and to approximately equal the flood tide velocity. Shad tracked to the east exhibited the same major behavior patterns but with the opposite directional bias.A hypothesis is presented suggesting that the location of the home river is achieved by means of a nonrandom search. Environmental clues indicative of the Connecticut River act to establish a preferred direction of displacement while the actual unidirectional displacement is achieved by reference to the rate and direction of tidal currents.

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.

Thermal comfort in high altitude Himalayan residential houses in Darjeeling, India – An adaptive approach

2019 ◽  
Vol 29 (1) ◽  
pp. 84-100 ◽  
Author(s):  
Samar Thapa
Keyword(s):  
Thermal Comfort ◽  
Field Survey ◽  
Thermal Sensation ◽  
Cold Climate ◽  
Himalayan Region ◽  
Survey Method ◽  
Adaptive Model ◽  
Eastern India ◽  
Comfort Zone ◽  
Chamber Study

The study of thermal comfort in buildings is required to maintain a stable and comfortable condition of the indoor environment. The climate chamber study used to determine thermal comfort is mathematically reproducible and robust, but exaggerative and hence is energy inefficient, whereas the adaptive model-based field survey method is exhaustive and bioclimatic specific. Although, several field survey-based thermal comfort studies have been reported from India, these studies were conducted mostly either in hot and humid or composite climatic condition, and very few research has been reported from cold climatic region, which lies mostly along the high altitudinal Himalayan region. In this paper, the results of field survey-based thermal comfort studies in residential houses of highly altitudinal Darjeeling Himalayan region in eastern India are presented. The study found that female subjects showed a lesser clothing cover but portrayed a higher discomfort with lower thermal sensation and higher comfort temperature. The comfort temperature as determined in this study did not comply with the ASHRAE standard 55 graphical method, and hence new comfort zone for regions with similar cold climate is proposed.

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