Helical Vertical Axis Wind Turbine Research Articles

Design and fabrication of a helical vertical axis wind turbine for electricity supply

Design and fabrication of a helical vertical axis wind turbine for electricity supply

Numerical Prediction on the Dynamic Response of a Helical Floating Vertical Axis Wind Turbine Based on an Aero-Hydro-Mooring-Control Coupled Model

Considering the aero-hydro-mooring-control coupled performance of a floating Vertical Axis Wind Turbine (VAWT), the numerical model of the floating helical VAWT system is established, and the fully coupled simulation program of the floating helical VAWT is developed. The aerodynamic load of the wind turbine system is calculated using the unsteady BEM model, and the hydrodynamic load is calculated using the 3D potential theory. The floating foundation is considered as a rigid body, and the blades and tower are considered as flexible bodies. Based on the Kane method of a multi-body system, the dynamic responses of the VAWT could be solved in the time domain. A variable speed control model considering efficiency and load is established to match the rotating speed with the wind speed, and it could maintain the target output power under the influence of turbulent wind and large-scale movement of the floating foundation. The control strategy of limiting the target speed change rate and low-pass filtering is adopted to ensure the rapid regulation of the wind turbine under low wind speed conditions and stable regulation under high wind speed conditions.

3D-CFD flow driven performance analysis of new non-cylindrical helical vertical axis wind turbine for fluctuating urban wind conditions

ABSTRACT Wind gusts are the serious parameters that need to be considered for the aerodynamic study of any wind turbine. This article investigates the performance of a new vertical axis wind turbine with non-cylindrical helical turbine blades for an unsteady gusty wind prevailing in urban and suburban environments. In this work, three-dimensional CFD analysis with dynamic mesh has been carried out for two gust velocities of 0.6 m/s and 2 m/s with a mean free stream velocity of 4 m/s. The behavior of the proposed helical turbine during start-up and steady operation was analyzed. The results show that the gust introduced during the start-up period aids in torque production, enabling it to reach the steady-state faster. The turbine reached the steady-state 54.71% earlier under gusty wind than under constant wind. However, on the scale of Cp, the turbine performed well under constant wind during the start-up period. The gust injection during the steady-state period showed a 1.97% increase in Cp of the turbine than under constant wind velocity.

Effect of Helix Angle on the Performance of Helical Vertical Axis Wind Turbine

The energy crisis has forced researchers to look for various non-conventional energy sources. Wind energy is one of the potential sources, and researchers have invested resources in developing different kinds of wind turbines. Vertical axis wind turbines (VAWT) have received less attention than their horizontal-axis counterparts. A helical-bladed VAWT is preferred because it makes perfect sense as an improvement in design, as they have higher azimuth angles of power generation capabilities. This paper studies the effects of the helix angle of blades in the aerodynamic performance of VAWT using 3D numerical simulations. Three different helix angles of 60°, 90°, and 120° of a three-bladed VAWT operating across different tip speed ratios were studied. Turbulence is modelled using a four-equation transition SST k-ω model (shear stress transport). The 60° helical-bladed VAWT was found to be better performing in comparison with all other helical-bladed and straight-bladed VAWT. The ripple effects on the shaft are also analysed using a standard deviation plot of the moment coefficient generated by a single blade over one complete cycle of its rotation. It was observed that the greater the helix angle, the lower the standard deviation. The paper also tries to analyse the percentage of power generated by each quartile of flow and the contribution of each section of the blade. Ansys FLUENT was employed for the entire study. A comparative study between different helical-bladed VAWT and straight-bladed VAWT was carried out along with wake structure analysis and flow contours for a better understanding of the flow field.

Structural Design and Stress Analysis of a Helical Vertical Axis Wind Turbine Blade

In this study, a Computational Fluid Dynamics (CFD) model is designed to investigate the structural analysis of a helical Vertical Axis Wind Turbine (VAWT) blade which is using National Advisory Committee for Aeronautics (NACA) 0018 airfoil and numerical calculations are conducted by using Comsol Multiphysics. The main objective of this study is to determine that the strength of the turbine blade against bending caused by increased wind speeds is sufficient for the selected turbine blade material. This paper presents also an investigation of the effects of different wind speeds on the structure of a helical VAWT blade that is fixed to the support arm which is attached to the VAWT’s main shaft. In this study, a turbine blade which is placed in an air flow field is subjected to approaching strong wind with different velocities. The model solves for the flow around the blade and the structural displacement due to the fluid load. This investigation consists of two main parts: Solving for the fluid flow around the turbine blade with a free stream velocities of 1, 3, 5, 7, and 9 m/s, and Studying the deformation of the turbine blade caused by the fluid load. The risk of failure according to the von Mises criterion for the ductile materials such as aluminum is also investigated.

Aerodynamic Analysis of a Helical Vertical Axis Wind Turbine

Vertical axis wind turbines (VAWTs) are gradually receiving more and more interest due to their lower sensitivity to the yawed wind direction. Compared with straight blades VAWT, blades with a certain helicity show a better aerodynamic performance and less noise emission. Nowadays computational fluid dynamics technology is frequently applied to VAWTs and gives results that can reflect real flow phenomena. In this paper, a 2D flow field simulation of a helical vertical axis wind turbine (HVAWT) with four blades has been carried out by means of a large eddy simulation (LES). The power output and fluctuation at each azimuthal position are studied with different tip speed ratio (TSR). The result shows that the variation of angle of attack (AOA) and blade-wake interaction under different TSR conditions are the two main reasons for the effects of TSR on power output. Furthermore, in order to understand the characteristics of the HVAWT along the spanwise direction, the 3D full size flow field has also been studied by the means of unsteady Reynold Averaged Navier-Stokes (U-RANS) and 3D effects on the turbine performance can be observed by the spanwise pressure distribution. It shows that tip vortex near blade tips and second flow in the spanwise direction also play a major role on the performance of VAWTs.

Construction of a helical vertical axis wind turbine for electricity supply

ABSTRACTIn an effort to find solutions for global energy crisis, an analysis on a helical vertical axis wind turbine was conducted with the consideration of renewables and energy efficiency. This study was carried out in two steps: the realization of the analytical calculation of a helical wind turbine power output which then informed the design and construction of the rotor blades. The project particularly aimed to address its use as the electricity supply for residential properties or any other places with less ideal economy conditions. The uncomplicated and highly accessible mechanism using basic materials is to give people to have a viable option on their own electricity production.

Reliability Estimation of Parameters of Helical Wind Turbine with Vertical Axis.

Due to the prolonged use of wind turbines they must be characterized by high reliability. This can be achieved through a rigorous design, appropriate simulation and testing, and proper construction. The reliability prediction and analysis of these systems will lead to identifying the critical components, increasing the operating time, minimizing failure rate, and minimizing maintenance costs. To estimate the produced energy by the wind turbine, an evaluation approach based on the Monte Carlo simulation model is developed which enables us to estimate the probability of minimum and maximum parameters. In our simulation process we used triangular distributions. The analysis of simulation results has been focused on the interpretation of the relative frequency histograms and cumulative distribution curve (ogive diagram), which indicates the probability of obtaining the daily or annual energy output depending on wind speed. The experimental researches consist in estimation of the reliability and unreliability functions and hazard rate of the helical vertical axis wind turbine designed and patented to climatic conditions for Romanian regions. Also, the variation of power produced for different wind speeds, the Weibull distribution of wind probability, and the power generated were determined. The analysis of experimental results indicates that this type of wind turbine is efficient at low wind speed.