Hydrodynamic performance and interaction eect of a vertical-axis tidal-current turbine

2015 ◽  
pp. 135-138
Keyword(s):  
Tidal Current ◽  
Vertical Axis ◽  
Hydrodynamic Performance ◽  
Tidal Current Turbine ◽  
Current Turbine

scholarly journals Hydrodynamic Performance Analysis of the Vertical Axis Twin-Rotor Tidal Current Turbine

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1694 ◽  
Author(s):  
Yong Ma ◽  
Chao Hu ◽  
Yulong Li ◽  
Lei Li ◽  
Rui Deng ◽  
...  
Keyword(s):  
Power Output ◽  
Tidal Current ◽  
Vertical Axis ◽  
Hydrodynamic Performance ◽  
Relative Distance ◽  
Output Efficiency ◽  
Simulation Results ◽  
Tidal Current Turbine ◽  
Current Turbine ◽  
Twin Rotor

The goal of this manuscript is to investigate the influence of relative distance between the twin rotors on the hydrodynamic performance of the vertical axis twin-rotor tidal current turbine. Computational fluid dynamics (CFD) simulations based on commercial software ANSYS-CFX have been performed to enhance the understanding of interactions between the twin-rotors. The interactions between the twin rotors are known to have increased the power output efficiency as a whole, and it is, therefore, of great significance to undertake deeper research. The simulation results are found to be consistent with similar research results in the literature in some aspects. The simulation results of stand-alone turbine and twin rotors are compared from three different aspects, including blade forces, power output efficiency and wake flow field. The results showed that the cyclic variations tendency of blade force coefficients of twin rotors is close to that of the stand-alone turbine. The average power output efficiency of the twin-rotors system is higher than that of the stand-alone turbine. The interactions between the turbines increase the power output of the twin turbine system as whole in a wide relative distance range. However, smaller relative distance between the twin rotors does not mean a bigger power output efficiency of such a system. The power out efficiency of such a system would decrease when the relative distance between the twin rotors exceeds the critical point. The power output of the twin rotors reaches the peak value when the ratio between the two main axis distance and diameter of the turbine is around 9/4. This research can provide a reference for the design and development of larger tidal power stations.

scholarly journals Optimization on the Law of Variable-Pitch Vertical-Axis Tidal Current Turbine

2018 ◽  
Vol 153 ◽  
pp. 03002
Author(s):  
Kong Fankai ◽  
Wang Liying ◽  
Zhang Di
Keyword(s):  
Tidal Current ◽  
Kinematic Model ◽  
Reference Value ◽  
Vertical Axis ◽  
Hydrodynamic Performance ◽  
Variable Pitch ◽  
Moment Coefficient ◽  
Tidal Current Turbine ◽  
Further Development ◽  
Current Turbine

In order to improve the hydrodynamic performance of the vertical-axis variable-pitch current turbine, with analyzing on the existing design mentality of blade control mechanism, an optimized law of variable-pitch vertical-axis tidal current turbine was given in terms of the instantaneous moment coefficient of the blade. A method for solving the lift - drag coefficient of Blade by wind - hole test data is given. The optimized kinematic model has a significant reference value for the further development of vertical axis turbine model test.

Structural Dynamic Analysis of a Tidal Current Turbine Using MBDyn

2018 ◽  
Author(s):  
Jun Leng ◽  
Ye Li
Keyword(s):  
Tidal Current ◽  
Interaction Analysis ◽  
Vertical Axis ◽  
Internal Force ◽  
Mode Shapes ◽  
Structural Dynamic ◽  
Tidal Current Energy ◽  
Integrated Simulation ◽  
Tidal Current Turbine ◽  
Current Turbine

In recent years, tidal current energy has gained wide attention for its abundant resource and environmentally friendly production. This study focuses on analyzing dynamic behavior of a three-bladed vertical axis tidal current turbine. The multibody dynamics code MBDyn is used in the numerical simulation. It performs the integrated simulation and analysis of nonlinear mechanical, aeroelastic, hydraulic and control problems by numerical integration. In this study, tidal current turbine is idealized as an assembly of flexible beams including axis of rotation, arms and blades. We firstly conduct a modal analysis on the tidal current turbine and validate the model with the results obtained by ANSYS. The natural frequencies of blades with different size parameters are compared and the corresponding mode shapes are presented. Next, a parametric study was performed to investigate the effect of internal force on the dynamic response. It is concluded that the proposed method is accurate and efficient for structural analysis of tidal current turbine and this flexible multibody model can be used in the fluid-structure-interaction analysis in the future.

Numerical study on energy-converging efficiency of the ducts of vertical axis tidal current turbine in restricted water

2020 ◽  
Vol 210 ◽  
pp. 107320 ◽  
Author(s):  
Wang Hua-Ming ◽  
Qu Xiao-Kun ◽  
Chen Lin ◽  
Tu Lu-Qiong ◽  
Wu Qiao-Rui
Keyword(s):  
Tidal Current ◽  
Numerical Study ◽  
Vertical Axis ◽  
Tidal Current Turbine ◽  
Current Turbine

scholarly journals 3-D Simulation of Vertical-Axial Tidal Current Turbine

2016 ◽  
Vol 23 (4) ◽  
pp. 73-83 ◽  
Author(s):  
Zhang Zhiyang ◽  
Ma Yong ◽  
Jiang Jin ◽  
Liu Weixing ◽  
Ma Qingwei
Keyword(s):  
Numerical Simulation ◽  
Tidal Current ◽  
Simple Structure ◽  
Hydrodynamic Performance ◽  
Control Technique ◽  
Fluid Field ◽  
Improve Accuracy ◽  
Tidal Current Turbine ◽  
Current Turbine ◽  
Dynamics Method

Abstract Vertical-axial tidal current turbine is the key for the energy converter, which has the advantages of simple structure, adaptability to flow and uncomplex convection device. It has become the hot point for research and application recently. At present, the study on the hydrodynamic performance of vertical-axial tidal current turbine is almost on 2-D numerical simulation, without the consideration of 3-D effect. CFD (Computational Fluid Dynamics) method and blade optimal control technique are used to improve accuracy in the prediction of tidal current turbine hydrodynamic performance. Numerical simulation of vertical-axial tidal current turbine is validated. Fixed and variable deflection angle turbine are comparatively studied to analysis the influence of 3-D effect and the character of fluid field and pressure field. The method, put the plate on the end of blade, of reduce the energy loss caused by 3-D effect is proposed. The 3-D CFD numerical model of vertical-axial tidal current turbine hydrodynamic performance in this study may provide theoretical, methodical and technical reference for the optimal design of turbine.

Preliminary Results of a Vortex Method for Stand-Alone Vertical Axis Marine Current Turbine

2007 ◽  
Author(s):  
Ye Li ◽  
Sander M. Calisal
Keyword(s):  
Wind Turbine ◽  
Tidal Current ◽  
Vortex Method ◽  
Vertical Axis ◽  
Small Scale ◽  
Discrete Vortex ◽  
Analysis And Design ◽  
Tidal Turbine ◽  
Tidal Current Turbine ◽  
Current Turbine

Tidal power technology has been dwarfed once to take hold in the late 1970’s, because the early generations were expensive at small scale and some applications (such as barrages) had negative environmental impacts. In a similar working manner as a wind turbine, a tidal current turbine has been recognized as a promising ocean energy conversion device in the past two decades. However, the industrialization process is still slow. One of the important reasons is lack of comprehensive turbine hydrodynamics analysis which can not only predict turbine power but also assess impacts on the surrounding areas. Although a lot can be learned from the marine propeller or the wind turbine studies, a systematic hydrodynamics analysis on a vertical axis tidal current turbine has not been reported yet. In this paper, we employed vortex method to calculate the performance of stand-alone vertical axis tidal turbine in term of power efficiency, torque and forces. This method focuses on power prediction, hydrodynamics analysis and design, which can provide information for turbines distribution planning in a turbine farm and other related studies, which are presented in Li and Calisal (2007), a companion paper in the conference. In this method, discrete vortex method is the core for numerical calculation. Free vortex wake structure, nascent vortex and vortex decay mechanism are discussed in detail. Good agreements in turbine efficiency comparison are obtained with both the newly-designed tidal turbine test in a towing tank and early wind turbine test.

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