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.

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

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.

Numerical Modelling of a Variable-Pitch, Vertical Axis Tidal Turbine Incorporating Flow Acceleration

2018 ◽  
Author(s):  
Brian Mannion ◽  
Seán B. Leen ◽  
Vincent McCormack ◽  
Stephen Nash
Keyword(s):  
Numerical Modelling ◽  
Bluff Body ◽  
Vertical Axis ◽  
Scale Model ◽  
Variable Pitch ◽  
Flow Acceleration ◽  
Sliding Mesh ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine ◽  
Power Curves

This paper presents details of the numerical modelling of a novel vertical axis tidal turbine that incorporates localised flow acceleration and variable-pitch blades. The focus of this research is to develop a computational fluid dynamics model of a 1:20 scale model of the device using ANSYS® Fluent®. A nested sliding mesh technique has been developed, with an outer sliding mesh being used to model the turbine and additional inner sliding meshes being used for each of the six blades. The turbine sliding mesh is embedded in an outer static domain which includes the flow accelerating bluff body. The variable pitch of the blades is specified in the model using a user-defined function (UDF) which faithfully reproduces the blade pitch during operation of the 1:20 scale model. Modelled power performance and velocity data are compared with experimental results obtained from scale model tests in a recirculating flume. The modelled power curves show good agreement with the measured data; the difference in maximum CP, for example, is just 5.7 %. The model also accurately reproduces measured flows downstream of the turbine. The high model accuracy means that it can now be used for design optimisation studies.

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.

The Hydrodynamic Characteristics of Free Variable-Pitch Vertical Axis Tidal Turbine

2012 ◽  
Vol 24 (6) ◽  
pp. 834-839 ◽  
Author(s):  
Xue-wei Zhang ◽  
Shu-qi Wang ◽  
Feng Wang ◽  
Liang Zhang ◽  
Qi-hu Sheng
Keyword(s):  
Vertical Axis ◽  
Free Variable ◽  
Hydrodynamic Characteristics ◽  
Variable Pitch ◽  
Tidal Turbine ◽  
Vertical Axis Tidal Turbine

scholarly journals Performance Improvement of a Darrieus Tidal Turbine with Active Variable Pitch

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 667
Author(s):  
Pierre-Luc Delafin ◽  
François Deniset ◽  
Jacques André Astolfi ◽  
Frédéric Hauville
Keyword(s):  
Performance Improvement ◽  
Angle Of Attack ◽  
Vertical Axis ◽  
Streamwise Velocity ◽  
Offshore Wind ◽  
Power Coefficient ◽  
Navier Stokes ◽  
Lower Efficiency ◽  
Variable Pitch ◽  
Tidal Turbine

Vertical axis turbines, also called Darrieus turbines, present interesting characteristics for offshore wind and tidal applications but suffer from vibrations and a lower efficiency than the more conventional horizontal axis turbines. The use of variable pitch, in order to control the angle of attack of the blades continuously during their rotation, is considered in this study to overcome these problems. 2D blade-resolved unsteady Reynolds-Averaged Navier–Stokes (RANS) simulations are employed to evaluate the performance improvement that pitching blades can bring to the optimal performance of a three-straight-blade vertical axis tidal turbine. Three pitching laws are defined and tested. They aim to reduce the angle of attack of the blades in the upstream half of the turbine. No pitching motion is used in the downstream half. The streamwise velocity, monitored at the center of the turbine, together with the measurement of the blades’ angle of attack help show the effectiveness of the proposed pitching laws. The decrease in the angle of attack in the upstream half of a revolution leads to a significant increase in the power coefficient (+40%) and to a better balance of the torque generated in the upstream and downstream halves. Both torque and thrust ripples are therefore significantly reduced.

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.

Sign in / Sign up

Export Citation Format

Share Document