Development Of Small Wind Turbines Research Articles

Location-optimized aerodynamic rotor design studies and development of small wind turbines

Location-optimized aerodynamic rotor design studies and development of small wind turbines

Aerodynamic Performance Analysis of Adaptive Drag-Lift Hybrid Type Vertical Axis Wind Turbine

In recent years, with the continuous development of new energy, how to efficiently use wind energy has received more and more market attention. Due to cost advantages, the development of small wind turbines is accelerating. Among them, the design and research of the airfoil design and research of the lift vertical axis wind turbine has matured, but because of the aerodynamic characteristics of the lift airfoil structure, it is impossible to start itself at low wind speed, resulting in the waste of low wind speed energy. Although the drag wind turbine has good self-starting performance, the wind energy utilization efficiency in the high-speed state is inefficient. Each has its own unique shortcomings, which directly affects the marketization of small wind turbines. In order to solve these problems, this paper presents a drag-lift hybrid type wind turbine structure based on an NACA0018 symmetrical airfoil, which can adaptively change the blade shape. This design can keep the blade in the drag shape under static and low speed conditions, and adaptively change the lift shape with the increase of speed. In addition, through the research method of CFD numerical simulation combined with physical experiments, the proposed wind turbine design is studied and analyzed from multiple angles. At the same time, the “6DOF + dynamic grid” setting is used to study the influence of the opening angle factor of the drag-lift hybrid blade on the self-starting performance, and the study shows that the design of the drag-lift hybrid blade proposed in this paper has a higher self-starting torque and lower starting wind speed than the traditional lifting blade, and it is observed that the drag-lift hybrid blade has the best self-starting performance when the opening angle of the blade is 80°. At the same time, the problem of switching the blade morphology of the drag-lift hybrid blade is also analyzed, along with how to use the spring to control all this adaptively. In order to better analyze the advantages of the drag-lift hybrid design proposed in this paper, a wind tunnel test was also carried out using the physical model, and the relationship between the leaf tip speed ratio and the wind energy utilization rate was obtained, which intuitively showed the improvement of the wind energy utilization rate of the drag-lift hybrid design compared with the traditional lift blade.

A pathway towards sustainable development of small capacity horizontal axis wind turbines – Identification of influencing design parameters & their role on performance analysis

Presently small wind turbines are receiving greater attention, due to the extensive promotion of decentralized power generation in a sustainable way by national and international organizations. However, there are many obstacles in commercializing these turbines on a large scale due to lower efficiencies of turbines associated with high vibrational losses, lack of technical knowledge with the manufacturers, cost criteria and lack of awareness among the end-users. This paper reviews the research works done in the design and development of small wind turbine blades, including diffusers and winglets addition. Performance & parametric analysis of airfoils, blades & wind turbines are presented comprehensively. Impact of maximum power point technique, effects of ambiance on the turbine performance, environmental impacts of small wind turbines and some novel concepts are presented in this review. Future research works to enhance the efficiency of small wind turbines using materials with high strength to weight ratio would pave the way for efficient utilization of available wind energy in the earth’s crust.

Preliminary wind resource assessment in South Sudan using reanalysis data and statistical methods

The purpose of this study is to make a preliminary assessment of the wind resource in South Sudan. This is mainly to get data on the quality of the wind resource at different locations in the country and investigate its suitability for the development of wind power generation projects of all sizes. Wind data for 33 locations, covering the period from 1981 to 2019, were requested from Modern-Era Retrospective analysis for Research and Applications version 2 or MERRA-2. The data were then analysed to produce a variety of statistics that describe the quality of the wind resource in each location. Long-term monthly and annual averages together with wind direction were computed for each location at a height of 10 m above ground level. Wind speeds were extrapolated to hub heights of 30 and 50 m above ground level and fitted to five different distribution functions to get the parameters for estimating wind power density. Results show that at 10 m above ground level, the long-term annual average wind speeds range between 5.08 m/s and 2.36 m/s while wind power density range between 128.36 W/m2and 14.39 W/m2. Development of utility-scale wind power plants is marginal in two locations while small-wind turbines development may be possible in the north-north eastern locations. Further research is proposed to explore the possibility of deployment of large-scale wind turbines at locations north-north east. Investigating the wind resource in other locations using alternative methods as well as possibility of development of small wind turbines is suggested.

Design and development of small wind turbine for power generation through high velocity exhaust air

Large scale wind turbines have been extensively examined for decades, but a very few studies have been conducted on small-scale wind turbines especially for the applications where artificial wind speed is of the order of 15 m per second. This study provides systematic effort towards design and development of small scale wind turbine aimed to operate at high wind speeds. The drag-based wind turbine has an enormous potential for small-scale power generation in cement manufacturing plant. It uses bag filter to prevent environmental pollution so as to let out the clean high velocity exhaust air through the duct. The work reported here presents to utilize exhaust air for electrical power generation. Exhaust air flow has been analysed in Ansys Fluent Software. Ansys Computational Fluid Dynamics (CFD) technology was adopted to evaluate the performance of the wind turbine. The results of torque assessment of the wind turbine in its static as well as dynamic condition have been presented. Experimental setup consisting turbine, generator, battery and load has been tested and validated.

Development and experimental verification of a 5 kW small wind turbine aeroelastic model

Aeroelastic modelling is regularly used in the design and analysis of commercial scale wind turbines, but has seen comparatively little use in the development of small wind turbines. Fewer studies still have considered experimental validation of model performance with field measurements. This study details the development of an aeroelastic model of a 5 kW horizontal-axis Aerogenesis turbine within FAST. The model includes rotor aerodynamics, blade and tower structural freedom, free-yaw tail fin dynamics, and a self-excited induction generator incorporating maximum power point tracking variable speed control. This model was compared to measured operating data to assess aerodynamic and structural performance. Blade loadings and deflections were simulated within 8% and 10% respectively at design conditions in the azimuthal domain. Simulated rotor speed control and tail fin motions were bounded by measured field data. The simulated control system model was found to act aggressively, with a mean over-prediction in tip speed ratio of 11%. Areas for future model improvement are discussed in this paper. The resulting aeroelastic model and methodologies presented here are expected to further the use of aeroelastic modelling in the small wind turbine field. Particular applications may include the verification of performance and design loads specified in IEC 61400.2.

Challenging low Reynolds - SWT blade aerodynamics

One of the main issues related to the design and development of small wind turbines (SWTs) is the low Reynolds number. Operation in the transitory regime makes the rotor aerodynamic analysis a challenging task. Project GUST (Generative Urban Small Turbine) realized currently at the Institute of Turbomachinery (Lodz University of Technology, Poland) is devoted to the development of SWT (D= 1.6 m) for low-Reynolds number (low wind speed) flow conditions. The emphasis is on the blade design, aiming at improving the rotor aerodynamic efficiency. The paper will highlight the rotor design process, based on contemporary methods of experiment-simulation integration approach and use of rapid manufacturing techniques. In-house wind tunnel measurements of a scaled model performance were executed. A numerical analysis using dedicated software (QBlade) was conducted in parallel. A comparison between the obtained results indicated that the chosen numerical tools are capable of providing a reliable output, even in complex, transitional flow conditions. Bearing in mind the above observations, QBlade was incorporated into the development process of a completely new blade geometry which would increase rotor performance. The selected design has indeed prove to show better power outcome in an additional experimental campaign.

Development of Small Wind Turbines with 500W Class Inner-Rotor Type Structure

We designed and fabricated a small wind turbine that can be used even in places where airflow is not strong, like in city centers and at home. In order to mount the slide type air collecting devices that can collect air flow, we plan to create an innerrotor type that is integrated with the blade and rotor, and is not exposed to external forces. The inner-rotor type wind turbine designed in this study is 500W class and is made up of 28 poles and 45 slots in order to reduce cogging torque. A characteristic experiment for the designed wind turbine has been carried out. Under the no-load condition, output voltages in a range from 400 rpm to 158.9V was generated, while experiments with 96Ω load showed that an output power generation of 527.6W was achieved. Designed and fabricated wind turbines in this study can be applied to a hybrid streetlight, and we plan to conduct a demonstration test to find whether it is useful in the domestic environment.

Development of small wind turbines for moving vehicles: Effects of flanged diffusers on rotor performance

The main object of this research is to develop a shrouded, small, horizontal-axis wind turbine for moving vehicles. Specifically, this study investigates the effects of flanged diffusers on rotor performance of small (30cm rotor diameter) wind turbines with different rotor solidities (20–60%) and wind speeds (10–20m/s). The experiments are conducted in a wind tunnel with and without a flanged diffuser. Results show that the flanged diffuser may significantly increase the power output, torque output, and rotor rotational speed of the wind turbine, largely depending on rotor solidity and wind speed. The higher the solidity and wind speed are, the smaller the effect of the flanged diffuser is. The 30%- and 40%-solidity rotors generate the largest power and torque outputs, respectively, while the 60%-solidity rotor has the lowest rotor rotational speed among the test rotors. These results provide some useful information when considering rotor-generator matching problems and the selection of rotor solidity for moving vehicles. This study also shows that a small wind turbine has the characteristics of low torque and high rotor rotational speed, and high rotor solidity for maximum power output compared to a conventional large wind turbine.

A Study for the development of Small Wind Turbine for Teaching Material

A Study for the development of Small Wind Turbine for Teaching Material