scholarly journals An Unsteady Boundary Element Model for Hydrodynamic Performance of a Multi-Blade Vertical-Axis Tidal Turbine

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1413 ◽  
Author(s):  
Guangnian Li ◽  
Qingren Chen ◽  
Hanbin Gu
Keyword(s):  
Boundary Element ◽  
Numerical Solutions ◽  
Vertical Axis ◽  
Element Model ◽  
Hydrodynamic Performance ◽  
Design And Optimization ◽  
Tidal Turbines ◽  
Proposed Model ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine

An unsteady boundary element model is developed to simulate the unsteady flow induced by the motion of a multi-blade vertical axis turbine. The distribution of the sources, bound vortices and wake vortices of the blades are given in detail. In addition, to make the numerical solution more robust, the Kutta condition is also introduced. The developed model is used to predict the hydrodynamic performance of a vertical axis tidal turbine and is validated by comparison with experimental data and other numerical solutions available in the literature. Good agreement is achieved and the calculation of the proposed model is simpler and more efficient than prior numerical solutions. The proposed model shows its capability for future profile design and optimization of vertical axis tidal turbines.

scholarly journals Study of Hydrodynamic Interference of Vertical-Axis Tidal Turbine Array

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1228
Author(s):  
Guangnian Li ◽  
Qingren Chen ◽  
Hanbin Gu
Keyword(s):  
Vertical Axis ◽  
Tidal Energy ◽  
Element Model ◽  
Hydrodynamic Performance ◽  
Maximum Efficiency ◽  
Hydrodynamic Characteristics ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
Vertical Axis Turbine ◽  
Vertical Axis Tidal Turbine

The hydrodynamic interference between tidal turbines must be considered when predicting their overall hydrodynamic performance and optimizing the layout of the turbine array. These factors are of great significance to the development and application of tidal energy. In this paper, the phenomenon of hydrodynamic interference of the tidal turbine array is studied by the hydrodynamic performance forecast program based on an unsteady boundary element model for the vertical-axis turbine array. By changing the relative positions of two turbines in the double turbine array to simulate the arrangement of different turbines, the hydrodynamic interference law between the turbines in the array and the influence of relative positions on the hydrodynamic characteristics in the turbine array are explored. The manner in which the turbines impact each other, the degree of influence, and rules for turbine array arrangement for maximum efficiency of the array will be discussed. The results of this study will provide technical insights to relevant researchers.

scholarly journals Study on Hydrodynamic Configuration Parameters of Vertical-Axis Tidal Turbine

2020 ◽  
Vol 27 (1) ◽  
pp. 116-125
Author(s):  
Li Guangnian ◽  
Qingren Chen ◽  
Yue Liu ◽  
Shanqiang Zhu ◽  
Qun Yu
Keyword(s):  
Vertical Axis ◽  
Hydrodynamic Performance ◽  
Numerical Code ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Variation Principle ◽  
Tip Speed Ratio ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine

AbstractIn this paper, a numerical code for predicting the hydrodynamic performance of vertical-axis tidal turbine array is developed. The effect of the tip speed ratio, solidity, and preset angle on the hydrodynamic performance are discussed using a series of calculations. The load principle of the rotor and the variation principle of the turbine power coefficient are studied. All these results can be considered as a reference for the design of vertical-axis tidal turbines.

scholarly journals Wake of a Ducted Vertical Axis Tidal Turbine in Turbulent Flows, LBM Actuator-Line Approach

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4273 ◽  
Author(s):  
Mikaël Grondeau ◽  
Sylvain Guillou ◽  
Philippe Mercier ◽  
Emmanuel Poizot
Keyword(s):  
Turbulent Flows ◽  
Vertical Axis ◽  
Tidal Currents ◽  
Eddy Simulation ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine ◽  
Ambient Turbulence ◽  
The Cost ◽  
Boltzmann Method

Vertical axis tidal turbines are devices that extract the kinetic energy from tidal currents. Tidal currents can be highly turbulent. Since ambient turbulence affects the turbine hydrodynamic, it is critical to understand its influence in order to optimize tidal farms. Actuator Line Model (ALM) combined with Large Eddy Simulation (LES) is a promising way to comprehend this phenomenon. In this article, an ALM was implemented into a Lattice Boltzmann Method (LBM) LES solver. This implementation gives good results for predicting the wake of a vertical axis tidal turbine placed into a turbulent boundary layer. The validated numerical configuration was then used to compute the wake of a real size ducted vertical axis tidal turbine. Several upstream turbulence rates were simulated. It was found that the shape of the wake is strongly influenced by the ambient turbulence. The cost-to-precision ratio of ALM-LBM-LES compared to fully resolved LBM-LES makes it a promising way of modeling tidal farms.

scholarly journals 3D Simulation with Flow-Induced Rotation for Non-Deformable Tidal Turbines

2021 ◽  
Vol 9 (3) ◽  
pp. 250
Author(s):  
Ilan Robin ◽  
Anne-Claire Bennis ◽  
Jean-Claude Dauvin
Keyword(s):  
Vertical Axis ◽  
Tidal Energy ◽  
Fluid Structure Interactions ◽  
Good Correspondence ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
Correct Direction ◽  
Convergence Study ◽  
Vertical Axis Tidal Turbine ◽  
Mesh Convergence

The overall potential for recoverable tidal energy depends partly on the tidal turbine technologies used. One of problematic points is the minimum flow velocity required to set the rotor into motion. The novelty of the paper is the setup of an innovative method to model the fluid–structure interactions on tidal turbines. The first part of this work aimed at validating the numerical model for classical cases of rotation (forced rotation), in particular, with the help of a mesh convergence study. Once the model was independent from the mesh, the numerical results were tested against experimental data for both vertical and horizontal tidal turbines. The results show that a good correspondence for power and drag coefficients was observed. In the wake, the vortexes were well captured. Then, the fluid drive code was implemented. The results correspond to the expected physical behavior. Both turbines rotated in the correct direction with a coherent acceleration. This study shows the fundamental operating differences between a horizontal and a vertical axis tidal turbine. The lack of experiments with the free rotation speed of the tidal turbines is a limitation, and a digital brake could be implemented to overcome this difficulty.

Comprehensive Study on Variable Pitch Vertical Axis Tidal Turbine

2012 ◽  
Vol 229-231 ◽  
pp. 778-782 ◽  
Author(s):  
Khalid Syed Shah ◽  
Liang Zhang
Keyword(s):  
Vertical Axis ◽  
Turbine Rotor ◽  
Hydrodynamic Performance ◽  
Navier Stokes ◽  
Design Parameters ◽  
Ongoing Research ◽  
Variable Pitch ◽  
Main Challenge ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine

To overcome the stalled effect and poor starting torque of fixed pitch Darrieus turbine, researchers invent variable pitch vertical axis tidal turbine (VATT). For tidal stream designers main challenge is that the design can sustain in hostile marine environment. Due to lift base design VATT is very critical for cavitation, so appropriate parameter selection can improve the hydrodynamic performance and life of the turbine. An attempt is made to optimize the design parameters of VATT for variable pitch using ANSYS CFX, hereafter CFX, which is based on a Reynolds-Averaged Navier-Stokes (RANS) model. A transient simulation is done for variable pitch VATT using Shear Stress Transport turbulence (SST) scheme. Main hydrodynamic parameters like torque T, combined moment CM, coefficients of performance CP and coefficient of torque CT, etc. are investigated. The modeling and meshing of turbine rotor is performed in ICEM-CFD. Mesh motion option is employed to achieve variable pitch phenomenon. This article is the one part of the ongoing research on turbine design and developments. The numerical simulation results are validated with analytical Matlab results performed by Edinburgh Design Ltd. The article concludes that CFX simulation is done accurately and major parameter selections for turbine development are feasible.

scholarly journals Influence of inlet line shape on hydrodynamic performance of tidal energy diffuser

2021 ◽  
Vol 39 (1) ◽  
pp. 93-100
Author(s):  
Meiyun Zheng ◽  
Zhuoyue Li ◽  
Peng Du ◽  
Haibao Hu ◽  
Xiaopeng Chen ◽  
...  
Keyword(s):  
Line Shape ◽  
Pressure Field ◽  
Vertical Axis ◽  
Tidal Energy ◽  
Hydrodynamic Performance ◽  
Engineering Practice ◽  
Energy Devices ◽  
Tidal Turbines ◽  
Different Types ◽  
Tidal Turbine

The installation of diffuser is an important way to improve the efficiency of tidal turbines, which is promising for engineering practice. In this paper, the open source code OpenFOAM is used as the platform. Numerical simulations are carried out to investigate the influence of the performance of the diffuser for the vertical axis tidal turbines. Several different types of diffusers are designed by distinguishing the line shape. Through systematic simulations, the influence of inlet line shape on the hydrodynamics performances of tidal energy diffuser is summarized. The velocity field, pressure field, etc. are analyzed to recover the flow modifications induced by the diffuser. The best line shape is finally found which can optimize the harnessing efficiency of the tidal turbine, which provides important clues for the development of tidal energy devices.

Design and Optimization of a Tidal Turbine and Farm

2018 ◽  
Author(s):  
Mohammed S. Mayeed
Keyword(s):  
Flow Simulation ◽  
Vertical Axis ◽  
Fatigue Analysis ◽  
Optimized Design ◽  
Florida Current ◽  
Lower Efficiency ◽  
Premature Failure ◽  
Design And Optimization ◽  
Failure Cost ◽  
Tidal Turbine

Tidal ocean power is a dependable and dense form of renewable energy which is a relatively underdeveloped field. This study optimizes a tidal turbine with respect to performance and economics, and then optimizes a farm to be economically feasible. It was determined that the southeastern portion of the Gulf Stream, Florida current, would be used for the tidal turbine system as it has some of the world’s fastest velocities and is relatively close to shore. The vertical axis designs were ruled out from extended research on turbine design for their lower efficiency in general. Only horizontal axis designs were tested in simulated environments. Using SolidWorks Flow Simulation and SolidWorks Simulation, turbine models were optimized and selected as having the potential for the greatest energy extraction. Static and fatigue analyses were conducted on the optimized models in order to prevent premature failure. Cost analysis was also performed on the turbine models and the model that had the lowest initial cost as well as the highest power generation was chosen for farm development. The optimized design produced reasonable amount of power considering varying velocities throughout the day having a diameter of about 30 m. Through fatigue analysis the optimized design also showed long enough lifetime so that a good return on investment can be acquired. The single optimized turbine was then placed in a farm, and the farm’s shape and arrangement were tested and optimized so that the best arrangement and distances between units could be found. It was found that a farm 1.25 kilometers by 20 kilometers consisting of 800 turbines would be optimal. The farm would produce an average of 249.33 megawatts for a profit of $294.88 million dollars annually. The farm would pay for itself in 7.12 years and have an expected life span of 26.1 years which was obtained through fatigue analysis.

CFD simulation of fixed and variable pitch vertical axis tidal turbine

2013 ◽  
Vol 12 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Qihu Sheng ◽  
Syed Shah Khalid ◽  
Zhimin Xiong ◽  
Ghazala Sahib ◽  
Liang Zhang
Keyword(s):  
Cfd Simulation ◽  
Vertical Axis ◽  
Variable Pitch ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine

10 kw Vertical Axis Wind Turbine Spindle Design and Optimization

2014 ◽  
Vol 487 ◽  
pp. 429-434 ◽  
Author(s):  
Qiao Mei Li ◽  
Yang Cao ◽  
Guo Qing Wu ◽  
Xing Hua Chen ◽  
Yan Hua Cao
Keyword(s):  
Wind Turbine ◽  
Vibration Mode ◽  
Vertical Axis ◽  
Element Model ◽  
High Load ◽  
Design Parameters ◽  
Vertical Axis Wind Turbine ◽  
Dead Weight ◽  
Design And Optimization ◽  
The Finite Element Model

The spindle of a 10 kw vertical axis wind turbine is designed in this paper, and the relevant geometric parameters is given, and build the geometry of the finite element model. Calculation of the spindle under wind load and dead weight , and analyse the spindle Von Mess stress, deformation nephogram, and give the former six order vibration mode of the spindle. Through the analysis, Then the design parameters of the spindle are optimized. and the optimized structure of spindle has been got. optimized spindle is in lower quality, more satisfy the requirement of wind turbine running under high load at the same time .

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