A computational assessment of the aerodynamic performance of a tilted Darrieus wind turbine (original) (raw)
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Performance assessment of Darrieus wind turbines with symmetric and cambered airfoils
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Aerodynamic performance prediction of Darrieus-type wind turbines
INCAS BULLETIN, 2010
The prediction of Darrieus wind turbine aerodynamic performances provides the necessary design and operational data base related to the wind potential. In this sense it provides the type of turbine suitable to the area where it is to be installed. Two calculation methods are analyzed for a rotor with straight blades. The first one is a global method that allows an assessment of the turbine nominal power by a brief calculation. This method leads to an overestimation of performances. The second is the calculation method of the gust factor and momentum which deals with the pale as being composed of different elements that don't influence each other. This method, developed based on the theory of the turbine blades, leads to values close to the statistical data obtained experimentally. The values obtained by the calculation method of gust factor-momentum led to the concept of a Darrieus turbine, which will be tested for different wind values in the INCAS subsonic wind tunnel.
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This paper presents a model for the evaluation of the optimal design of Darrieus vertical axis wind turbine by CFD analysis and experimental tests, through analyzing six models of Darrieus wind turbines, number of blades and tip speed ratio. For this purpose, a full investigation campaign has been carried out through a systematic comparison of numerical simulations with wind tunnel experiments data. The airfoil profile used in the turbine blades was DU06W200 and constant geometry dimensions to turbines. The experiments were done for all Darrieus wind turbine models by using a subsonic wind tunnel under open type test section with airflow speed range (3-7.65) m/s and different tip speed ratio TSR. The results show that Darrieus WT straight type can be self-starting at the wind velocity 3 m/s, where other types cannot be starting at less than wind speed 5 m/s. The rotational speed (N) increases for all models with the wind velocity increase. The power coefficient (CP) increases when t...
International Journal of Low-Carbon Technologies
The power output of a straight-bladed H-rotor Darrieus vertical axis wind turbine (HDVAWT) is explored in this article. The comparisons are performed between the NACA0018 airfoil and a series of Kline Fogelman modified NACA0018 airfoils. The computational fluid dynamics findings are first cross-checked with the experimental data, and the computational processes are validated as a consequence. Then, in CATIA, 12 airfoils were constructed by modifying the step thickness, step placement and trailing edge form to get an efficient model for the wind turbine. The approved computational processes are applied to all 13 models, and the results are obtained. In comparison to the NACA 0018 airfoil, the KFm3 airfoil with 12% step thickness and a rectangular trailing edge demonstrated a 47% efficiency under 6.65 m/s wind velocity and a rotational velocity of 120 RPM. The KFm3 airfoil also performed better when tested at 80 and 162 RPMs. Thus, the final HDVAWT has been presented for real-time app...
Energy Conversion and Management, 2017
The global warming threats, the presence of policies on support of renewable energies, and the desire for clean smart cities are the major drives for most recent researches on developing small wind turbines in urban environments. VAWTs (vertical axis wind turbines) are most appealing for energy harvesting in the urban environment. This is attributed due to structural simplicity, wind direction independency, no yaw mechanism required, withstand high turbulence winds, cost effectiveness, easier maintenance, and lower noise emission of VAWTs. This paper reviews recent published works on CFD (computational fluid dynamic) simulations of Darrieus VAWTs. Recommendations and guidelines are presented for turbulence modeling, spatial and temporal discretization, numerical schemes and algorithms, and computational domain size. The operating and geometrical parameters such as tip speed ratio, wind speed, solidity, blade number and blade shapes are fully investigated. The purpose is to address different progresses in simulations areas such as blade profile modification and optimization, wind turbine performance augmentation using guide vanes, wind turbine wake interaction in wind farms, wind turbine aerodynamic noise reduction, dynamic stall control, self-starting characteristics, and effects of unsteady and skewed wind conditions.
Review on Aerodynamic Performance Evaluation of Straight Blade Vertical Axis Wind Turbine.pdf
As the energy crisis is getting severe in the world it will be important to investigate alternative methods of generating power in ways different than, fossil fuels. In fact, one of the biggest sources of energy is all around us all of the time, the wind. Currently, horizontal axis wind turbines (HAWT) dominate the wind energy market due to their large size and high power generation characteristics. However, vertical axis wind turbines (VAWT) are capable of producing a lot of power, and offer many advantages for small-scale and domestic applications. One drawback of DARRIEUS type VAWT is their inability to reliably selfstart at low tip speed ratio. The details of different configurations and performance evaluation techniques along with the major findings of researchers on vertical axis wind turbines are reviewed in this paper. The main purpose of the study described here is to investigate effect of different design parameter on performance evaluation of VAWT.