Methods for Improving Lift Force of Wind Turbine Aerofoil Blades during Low Wind Speed Conditions – A Review

2015 ◽  
Vol 787 ◽  
pp. 134-137
Author(s):  
S.P.R. Febi Ponwin ◽  
S. Rajkumar

Wind energy is one of the promising renewable energy resources. The challenges in utilizing the renewable energy sources are making them reliable with good efficiency. Wind turbine plays a major role in industrial power supply during heavy wind conditions. However, in domestic applications, the small scale wind turbine has major issue of low starting torque due to low wind speed near the ground surface. These conditions make the air motion as laminar flow with the Reynolds number less than 5x105. Hence, in some adverse condition there is a laminar flow separation which increases the drag and consequently reduces the lift force. This paper gives a comprehensive review on the investigations that are being carried out on low Reynolds number regime aerofoil and laminar separation bubble to enhance the lift force especially at low wind speed conditions.

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Prachi R. Prabhukhot ◽  
Aditya R. Prabhukhot

The power generated in wind turbine depends on wind speed and parameters of blade geometry like aerofoil shape, blade radius, chord length, pitch angle, solidity, etc. Aerofoil selection is the crucial factor in establishing the efficient wind turbine. More than one aerofoil in a blade can increase the efficiency further. Previous studies of different aerofoils have shown that efficiency of small scale wind turbine increases when NREL S822 aerofoil is used for wind speed on and above 10 m/s. This paper introduces a study on effect of low wind speed (V = 5 m/s) on performance of blade profile. Aerofoils NREL S822/S823 are used for microwind turbine with S823 near root and S822 near tip. Blade of 3 m radius with spherical tubercles over entire span is analyzed considering 5 deg angle of attack. The computational fluid dynamics (CFD) simulation was carried out using ANSYS fluent to study the behavior of blade profile at various contours. The study shows that blade experiences maximum turbulence and minimum pressure near trailing edge of the tip of blade. The region also experiences maximum velocity of the flow. These factors result in pushing the aerofoil in upward direction for starting the wind turbine to rotate at the speed as low as 5 m/s.


Author(s):  
R. S. Amano ◽  
Ryan J. Malloy

Recently there has been an increase in the demand for the utilization of clean renewable energy sources. This is a direct result of a rise in oil prices and an increased awareness of human induced climate change. Wind energy has been shown to be one of the most promising sources of renewable energy. With current technology, the low cost of wind energy is competitive with more conventional sources of energy such as coal. This however is only true in areas of high wind density. These areas are not as abundant and therefore the number of profitable sites is limited. This paper explores the possibility increasing the number of profitable sites by optimizing wind turbine blade design for low wind speed areas. The two methods of optimization that are investigated are first, optimizing the angle of attack and chord length for a given airfoil cross section at different positions along the blade and second implementing a swept blade profile. The torque generated from a blade using only the first optimization technique is compared to that generated from a blade using both techniques as well as that generated by NTK500/41 turbine using LM19.1 blades. Performance will be investigated using the CFD solver FLUENT.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1463 ◽  
Author(s):  
Kehinde A. Adeyeye ◽  
Nelson Ijumba ◽  
Jonathan S. Colton

The global population is moving away from fossil fuel technologies due to their many disadvantages, such as air pollution, greenhouse gases emission, global warming, acid rain, health problems, and high costs. These disadvantages make fossil fuels unsustainable. As a result, renewable energy is becoming more attractive due to its steadily decreasing costs. Harnessing renewable energy promises to meet the present energy demands of the African continent. The enormous renewable energy potential available across the African continent remains largely untapped, especially for wind energy. However, marginal and fair wind speeds and power densities characterize African wind energy resulting in low and unsustainable power in many areas. This research develops a techno-economic model for wind energy cost analysis for a novel, Ferris wheel-based wind turbine. The model is used to techno-economically analyze the siting of wind turbine sites in low wind speed areas on the African continent. The wind turbine’s technical performance is characterized by calculating the annual energy production and the capacity factor using the wind Weibull probability distribution of the cities and theoretical power curve of the wind turbine. Its economic performance is evaluated using annualized financial return on investment, simple payback period, and levelized cost of electricity. The techno-economic model is validated for 21 African cities and shows that the Ferris wheel-based design is very competitive with four current, commercial wind turbines, as well as with other sources of energy. Hence, the new wind turbine may help provide the economical, clean, renewable energy that Africa needs.


Author(s):  
Wibby Aditya Putra Utama ◽  
Yohandri Bow ◽  
M. Syahirman Yusi

The demand for electrical energy that continues to increase along with the advancement of civilization and also the increasing number of people as well as the reduced level of fulfillment and availability of non-renewable energy sources, it is necessary to have renewable energy resources that capable of fulfill these energy demand in a more environmental friendly. One of the natural energies that we can use is wind energy, which is easy to get and lasts continuously. This research examines the comparison of the power generated from the vertical axis wind turbine savonius type and darrieus H type. The wind that use in this research get from from the fan. The test is doing by varying the wind speed by adjusting the fan speed. The fan is directed to the wind turbine to rotate the wind turbine. To measure the wind speed produced by the fan, a digital anemometer is used. The result of this research is the relation data of voltage to rpm and voltage to wind speed of wind turbine.


2021 ◽  
Author(s):  
Sahishnukumar Shah

The small-scale vertical axis wind turbine is designed and modeled in this project, considering all aspects of wind turbine such as Blade design, stator design, rotor design and converter system design. Electric Power has become a prime necessity for any country for economic development. The conventional fuel sources for power generation are depleting fast. The favorable alternatives are renewable energy sources. Although more invention has to be carried out in the field of renewable energy sources, every little effort in this direction may provide a solution to reach most economical power generation point. Hence the same topic was selected for Masters Project. The goal of this project is to design a small scale Vertical Axis Wind Turbine, which is capable of producing electrical power even with low wind velocity. It can be placed on road dividers, sidetracks of train or remote places i.e. villages, military camps, where it is not economical to transmit power from power plants. Implementation of such project would reduce the dependence of an industry or remote houses, on electricity board.


Author(s):  
Ahmed S A Badawi ◽  
Nurul Fadzlin Hasbullah ◽  
Siti Yusoff ◽  
Aisha Hashim ◽  
Mohammed Elamassie

In this paper power energy had been estimated based on actual wind speed records in a coastal city in Palestine Ashdod. The main aims of this study to determine the feasibility of wind turbine and to estimate payback period. Therefore, to encourage investment in renewable energy in Palestine. The daily average wind speed data had been analyzed and fitted to the Weibull probability distribution function. The parameters of Weibull had been calculated by author using Graphical method the applied example wind turbine is 5kw wind turbine generator this is suitable turbine for small scale based on wind speed records on the coastal plain of Palestine. This study calculated the energy that can produce from wind turbine to estimate the revenue of any possible project in wind energy conversion system based on unit area. Energy has been calculated wind energy using two different method based on Weibull data and measured data. The total amount of energy for 2010 is 10749.8 kw.hr/m2 based on measured wind speed. Payback period for the project in wind energy turbines is around 3 years which make the generation electricity possible for small scale but not commercial. This study will lead to assess the wind energy production in Palestine to encourage investment in renewable energy sectors.


2021 ◽  
Author(s):  
Sahishnukumar Shah

The small-scale vertical axis wind turbine is designed and modeled in this project, considering all aspects of wind turbine such as Blade design, stator design, rotor design and converter system design. Electric Power has become a prime necessity for any country for economic development. The conventional fuel sources for power generation are depleting fast. The favorable alternatives are renewable energy sources. Although more invention has to be carried out in the field of renewable energy sources, every little effort in this direction may provide a solution to reach most economical power generation point. Hence the same topic was selected for Masters Project. The goal of this project is to design a small scale Vertical Axis Wind Turbine, which is capable of producing electrical power even with low wind velocity. It can be placed on road dividers, sidetracks of train or remote places i.e. villages, military camps, where it is not economical to transmit power from power plants. Implementation of such project would reduce the dependence of an industry or remote houses, on electricity board.


Author(s):  
Mohammed S. Mayeed ◽  
Adeel Khalid

Wind energy has been identified as an important source of renewable energy. In this study, several wind turbine designs have been analyzed and optimized designs have been proposed for low wind speed areas around the world mainly for domestic energy consumption. The wind speed range of 4–12 mph is considered, which is selected based on the average wind speeds in the Atlanta, GA and surrounding areas. These areas have relatively low average wind speeds compared to various other parts of the United States. Traditionally wind energy utilization is limited to areas with higher wind speeds. In reality a lot of areas in the world have low average wind speeds and demand high energy consumption. In most cases, wind turbines are installed in remote offshore or away from habitat high wind locations, causing heavy investment in installation and maintenance, and loss of energy transfer over long distance. A few more advantages of small scale wind turbines include reduced visibility, less noise and reduced detrimental environmental effects such as killing of birds, when compared to traditional large turbines. With the latest development in wind turbine technology it is now possible to employ small scale wind turbines that have much smaller foot print and can generate enough energy for small businesses or residential applications. The low speed wind turbines are typically located near residential areas, and are much smaller in sizes compared to the large out of habitat wind turbines. In this study, several designs of vertical and horizontal axes wind turbines are modeled using SolidWorks e.g. no-airfoil theme, airfoil blade, Savonius rotor etc. Virtual aerodynamic analysis is performed using SolidWorks Flow simulation software, and then optimization of the designs is performed based on maximizing the starting rotational torque and ultimate power generation capacity. From flow simulations, forces on the wind turbine blades and structures are calculated, and used in subsequent stress analysis to confirm structural integrity. Critical insight into low wind speed turbines is obtained using various configurations, and optimized designs have been proposed. The study will help in the practical and effective utilization of wind energy for the areas around the globe having low average wind speeds.


2019 ◽  
Vol 3 (1) ◽  
pp. 1-12
Author(s):  
Lauren K. D’Souza ◽  
William L. Ascher ◽  
Tanja Srebotnjak

Native American reservations are among the most economically disadvantaged regions in the United States; lacking access to economic and educational opportunities that are exacerbated by “energy insecurity” due to insufficient connectivity to the electric grid and power outages. Local renewable energy sources such as wind, solar, and biomass offer energy alternatives but their implementation encounters barriers such as lack of financing, infrastructure, and expertise, as well as divergent attitudes among tribal leaders. Biomass, in particular, could be a source of stable base-load power that is abundant and scalable in many rural communities. This case study examines the feasibility of a biomass energy plant on the Cocopah reservation in southwestern Arizona. It considers feedstock availability, cost and energy content, technology options, nameplate capacity, discount and interest rates, construction, operation and maintenance (O&M) costs, and alternative investment options. This study finds that at current electricity prices and based on typical costs for fuel, O&M over 30 years, none of the tested scenarios is presently cost-effective on a net present value (NPV) basis when compared with an alternative investment yielding annual returns of 3% or higher. The technology most likely to be economically viable and suitable for remote, rural contexts—a combustion stoker—resulted in a levelized costs of energy (LCOE) ranging from US$0.056 to 0.147/kWh. The most favorable scenario is a combustion stoker with an estimated NPV of US$4,791,243. The NPV of the corresponding alternative investment is US$7,123,380. However, if the tribes were able to secure a zero-interest loan to finance the plant’s installation cost, the project would be on par with the alternative investment. Even if this were the case, the scenario still relies on some of the most optimistic assumptions for the biomass-to-power plant and excludes abatement costs for air emissions. The study thus concludes that at present small-scale, biomass-to-energy projects require a mix of favorable market and local conditions as well as appropriate policy support to make biomass energy projects a cost-competitive source of stable, alternative energy for remote rural tribal communities that can provide greater tribal sovereignty and economic opportunities.


Author(s):  
Marcus Wiens ◽  
Sebastian Frahm ◽  
Philipp Thomas ◽  
Shoaib Kahn

AbstractRequirements for the design of wind turbines advance facing the challenges of a high content of renewable energy sources in the public grid. A high percentage of renewable energy weaken the grid and grid faults become more likely, which add additional loads on the wind turbine. Load calculations with aero-elastic models are standard for the design of wind turbines. Components of the electric system are usually roughly modeled in aero-elastic models and therefore the effect of detailed electrical models on the load calculations is unclear. A holistic wind turbine model is obtained, by combining an aero-elastic model and detailed electrical model into one co-simulation. The holistic model, representing a DFIG turbine is compared to a standard aero-elastic model for load calculations. It is shown that a detailed modelling of the electrical components e.g., generator, converter, and grid, have an influence on the results of load calculations. An analysis of low-voltage-ride-trough events during turbulent wind shows massive increase of loads on the drive train and effects the tower loads. Furthermore, the presented holistic model could be used to investigate different control approaches on the wind turbine dynamics and loads. This approach is applicable to the modelling of a holistic wind park to investigate interaction on the electrical level and simultaneously evaluate the loads on the wind turbine.


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