Starting System for Darrieus Water Turbine of Tidal Stream Electricity Generation

2016 ◽  
Author(s):  
Seiji Shimizu ◽  
Masayuki Fujii ◽  
Tetsuya Sumida ◽  
Kenji Sasa ◽  
Yasuhiro Kimura ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Electricity Generation ◽  
Lift Coefficient ◽  
Vertical Axis ◽  
Cylindrical Shape ◽  
Water Turbine ◽  
Tidal Stream ◽  
Tidal Stream Turbine ◽  
Original Experimental Data

Darrieus type vertical axis water turbine in a cylindrical shape which consists of some straight blades is simple, efficient and easy to install a generator upward. However, it has difficulty in starting revolution. As a method to cope with such a problem, a starting revolution assist mechanism was fabricated and set on a prototype of the turbine. Assist experiment was carried out. It resulted helping well the starting revolution. The improved prototype of tidal stream turbine can generate 1.4 W under a water flow of 1 m/s where impossible to self-start. Besides that, Darrieus water turbine’s generating torque property was investigated by the famous original experimental data of lift coefficient Cl and drag coefficient Cd for straight blades of NACA63 3-018 cross section. It was found that setting two or four blades in a turbine would help to improve the difficulty of starting revolution.

6-DOF Numerical Simulation of the Vertical-Axis Water Turbine

2011 ◽  
Author(s):  
Xin Wang ◽  
Xianwu Luo ◽  
Baotang Zhuang ◽  
Weiping Yu ◽  
Hongyuan Xu
Keyword(s):  
Vertical Axis ◽  
Hydrodynamic Performance ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Test Model ◽  
Tip Speed Ratio ◽  
Water Turbine ◽  
Tidal Stream ◽  
Static Head ◽  
Tidal Stream Turbine

Recent years, the vertical-axis water turbine (VAWT) is widely used for converting the kinetic energy of the moving water in open flow and with low static head like river and tidal sites. Conventional numerical methods such as disk-stream tube method and vortex panel method have some drawbacks to predict the behaviors and characteristics of the vertical-axis tidal stream turbine. This paper had treated the hydrodynamic performance of a VAWT model experimentally and numerically. Based on the present research, a 6-DOF method coupled with CFD suitable to simulate the rotor movement and predict the hydraulic performance for a VAWT was proposed. Compared with the experiments, the numerical results for the performance of the VAWT model were reasonable. It is also noted that there is a maximum power coefficient near tip speed ratio of 2.5 for the test model.

Fusion and Breakup Reactions of 17S + 208Pb and 15C + 232ThHalo Nuclei Systems

2015 ◽  
Vol 11 (2) ◽  
pp. 2972-2978
Author(s):  
Fouad A. Majeed ◽  
Yousif A. Abdul-Hussien
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Recent Experimental Data ◽  
Barrier Distribution ◽  
Coupled Channel ◽  
Total Fusion ◽  
Full Quantum

In this study the calculations of the total fusion reaction cross section have been performed for fusion reaction systems 17F + 208Pb and 15C + 232Th which involving halo nuclei by using a semiclassical approach.The semiclassical treatment is comprising the WKB approximation to describe the relative motion between target and projectile nuclei, and Continuum Discretized Coupled Channel (CDCC) method to describe the intrinsic motion for both target and projectile nuclei. For the same of comparsion a full quantum mechanical clacualtions have been preforemd using the (CCFULL) code. Our theorticalrestuls are compared with the full quantum mechaincialcalcuations and with the recent experimental data for the total fusion reaction  checking the stability of the distancesThe coupled channel calculations of the total fusion cross section σfus, and the fusion barrier distribution Dfus. The comparsion with experiment proves that the semiclassiacl approach adopted in the present work reproduce the experimental data better that the full quantal mechanical calcautions. 

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

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