The Experts below are selected from a list of 21444 Experts worldwide ranked by ideXlab platform
Takuji Kasuya - One of the best experts on this subject based on the ideXlab platform.
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effect of solidity on Aerodynamic Forces around straight bladed vertical axis wind turbine by wind tunnel experiments depending on number of blades
Renewable Energy, 2016Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kento Shimizu, Tatsuhiko Ogasawara, Alisa Nakai, Takuji KasuyaAbstract:The prediction of Aerodynamic Forces around straight-bladed Vertical Axis Wind Turbines (VAWT) is important for wind turbine applications. This paper focused on evaluating the Aerodynamic Forces acting on a single blade, depending on the different numbers of blades in wind tunnel experiments. In this study, numbers of blades were from two to five and the cross-sectional shape of the tested airfoil was a NACA0021. Firstly, the power coefficient was measured by a torque meter and a six-component balance. Secondly, pressures acting on the surface of rotor blades were measured during rotation by multiport pressure devices. Then, the evolutions of normal coefficient, tangential coefficient and lift-to-drag ratio CL/CD, which were obtained from pressure distributions, were discussed. Finally, the power coefficients calculated by pressure distributions were compared with the experiment data of the torque meter and the six-component balance. The results showed that the pressure difference substantially decreased with the increase of solidity. In addition, the values of six-component balance and torque meter showed smaller values than those calculated by pressure distributions. In words, these results provided theoretical significance towards the development of a simple design for straight-bladed VAWT.
Takao Maeda - One of the best experts on this subject based on the ideXlab platform.
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effect of solidity on Aerodynamic Forces around straight bladed vertical axis wind turbine by wind tunnel experiments depending on number of blades
Renewable Energy, 2016Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kento Shimizu, Tatsuhiko Ogasawara, Alisa Nakai, Takuji KasuyaAbstract:The prediction of Aerodynamic Forces around straight-bladed Vertical Axis Wind Turbines (VAWT) is important for wind turbine applications. This paper focused on evaluating the Aerodynamic Forces acting on a single blade, depending on the different numbers of blades in wind tunnel experiments. In this study, numbers of blades were from two to five and the cross-sectional shape of the tested airfoil was a NACA0021. Firstly, the power coefficient was measured by a torque meter and a six-component balance. Secondly, pressures acting on the surface of rotor blades were measured during rotation by multiport pressure devices. Then, the evolutions of normal coefficient, tangential coefficient and lift-to-drag ratio CL/CD, which were obtained from pressure distributions, were discussed. Finally, the power coefficients calculated by pressure distributions were compared with the experiment data of the torque meter and the six-component balance. The results showed that the pressure difference substantially decreased with the increase of solidity. In addition, the values of six-component balance and torque meter showed smaller values than those calculated by pressure distributions. In words, these results provided theoretical significance towards the development of a simple design for straight-bladed VAWT.
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effect of number of blades on Aerodynamic Forces on a straight bladed vertical axis wind turbine
Energy, 2015Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kazuma Furukawa, Masayuki YamamotoAbstract:Small wind turbine performance and safety standard for straight-bladed Vertical Axis Wind Turbine (VAWT) have not been developed in the world because of the lack of fundament experimental data. This paper focuses on the evaluation of Aerodynamic Forces depending on several numbers of blades in wind tunnel experiment. In the present study, the test airfoil of blade is symmetry airfoil of NACA 0021 and the number of blades is from two to five. Pressure acting on the surface of rotor blade is measured during rotation by multiport pressure devices and transmitted to a stationary system through wireless LAN. And then, the Aerodynamic Forces (tangential force, normal force et al.) are discussed as a function of azimuth angle, achieving a quantitative analysis of the effect of numbers of blades. Finally, the loads are compared with the experimental data of six-component balance. As a result, it is clarified that the power coefficient decreases with the increase of numbers of blades. Furthermore, the power which is absorbed from wind by wind turbine mainly depends on upstream region of azimuth angle of θ = 0°∼180°. In this way, these results are very important for developing the simple design equations and applications for straight-bladed VAWT.
Yasunari Kamada - One of the best experts on this subject based on the ideXlab platform.
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effect of solidity on Aerodynamic Forces around straight bladed vertical axis wind turbine by wind tunnel experiments depending on number of blades
Renewable Energy, 2016Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kento Shimizu, Tatsuhiko Ogasawara, Alisa Nakai, Takuji KasuyaAbstract:The prediction of Aerodynamic Forces around straight-bladed Vertical Axis Wind Turbines (VAWT) is important for wind turbine applications. This paper focused on evaluating the Aerodynamic Forces acting on a single blade, depending on the different numbers of blades in wind tunnel experiments. In this study, numbers of blades were from two to five and the cross-sectional shape of the tested airfoil was a NACA0021. Firstly, the power coefficient was measured by a torque meter and a six-component balance. Secondly, pressures acting on the surface of rotor blades were measured during rotation by multiport pressure devices. Then, the evolutions of normal coefficient, tangential coefficient and lift-to-drag ratio CL/CD, which were obtained from pressure distributions, were discussed. Finally, the power coefficients calculated by pressure distributions were compared with the experiment data of the torque meter and the six-component balance. The results showed that the pressure difference substantially decreased with the increase of solidity. In addition, the values of six-component balance and torque meter showed smaller values than those calculated by pressure distributions. In words, these results provided theoretical significance towards the development of a simple design for straight-bladed VAWT.
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effect of number of blades on Aerodynamic Forces on a straight bladed vertical axis wind turbine
Energy, 2015Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kazuma Furukawa, Masayuki YamamotoAbstract:Small wind turbine performance and safety standard for straight-bladed Vertical Axis Wind Turbine (VAWT) have not been developed in the world because of the lack of fundament experimental data. This paper focuses on the evaluation of Aerodynamic Forces depending on several numbers of blades in wind tunnel experiment. In the present study, the test airfoil of blade is symmetry airfoil of NACA 0021 and the number of blades is from two to five. Pressure acting on the surface of rotor blade is measured during rotation by multiport pressure devices and transmitted to a stationary system through wireless LAN. And then, the Aerodynamic Forces (tangential force, normal force et al.) are discussed as a function of azimuth angle, achieving a quantitative analysis of the effect of numbers of blades. Finally, the loads are compared with the experimental data of six-component balance. As a result, it is clarified that the power coefficient decreases with the increase of numbers of blades. Furthermore, the power which is absorbed from wind by wind turbine mainly depends on upstream region of azimuth angle of θ = 0°∼180°. In this way, these results are very important for developing the simple design equations and applications for straight-bladed VAWT.
Junsuke Murata - One of the best experts on this subject based on the ideXlab platform.
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effect of solidity on Aerodynamic Forces around straight bladed vertical axis wind turbine by wind tunnel experiments depending on number of blades
Renewable Energy, 2016Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kento Shimizu, Tatsuhiko Ogasawara, Alisa Nakai, Takuji KasuyaAbstract:The prediction of Aerodynamic Forces around straight-bladed Vertical Axis Wind Turbines (VAWT) is important for wind turbine applications. This paper focused on evaluating the Aerodynamic Forces acting on a single blade, depending on the different numbers of blades in wind tunnel experiments. In this study, numbers of blades were from two to five and the cross-sectional shape of the tested airfoil was a NACA0021. Firstly, the power coefficient was measured by a torque meter and a six-component balance. Secondly, pressures acting on the surface of rotor blades were measured during rotation by multiport pressure devices. Then, the evolutions of normal coefficient, tangential coefficient and lift-to-drag ratio CL/CD, which were obtained from pressure distributions, were discussed. Finally, the power coefficients calculated by pressure distributions were compared with the experiment data of the torque meter and the six-component balance. The results showed that the pressure difference substantially decreased with the increase of solidity. In addition, the values of six-component balance and torque meter showed smaller values than those calculated by pressure distributions. In words, these results provided theoretical significance towards the development of a simple design for straight-bladed VAWT.
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effect of number of blades on Aerodynamic Forces on a straight bladed vertical axis wind turbine
Energy, 2015Co-Authors: Takao Maeda, Yasunari Kamada, Junsuke Murata, Kazuma Furukawa, Masayuki YamamotoAbstract:Small wind turbine performance and safety standard for straight-bladed Vertical Axis Wind Turbine (VAWT) have not been developed in the world because of the lack of fundament experimental data. This paper focuses on the evaluation of Aerodynamic Forces depending on several numbers of blades in wind tunnel experiment. In the present study, the test airfoil of blade is symmetry airfoil of NACA 0021 and the number of blades is from two to five. Pressure acting on the surface of rotor blade is measured during rotation by multiport pressure devices and transmitted to a stationary system through wireless LAN. And then, the Aerodynamic Forces (tangential force, normal force et al.) are discussed as a function of azimuth angle, achieving a quantitative analysis of the effect of numbers of blades. Finally, the loads are compared with the experimental data of six-component balance. As a result, it is clarified that the power coefficient decreases with the increase of numbers of blades. Furthermore, the power which is absorbed from wind by wind turbine mainly depends on upstream region of azimuth angle of θ = 0°∼180°. In this way, these results are very important for developing the simple design equations and applications for straight-bladed VAWT.
Anders Pape Moller - One of the best experts on this subject based on the ideXlab platform.
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sexual dimorphism and population differences in structural properties of barn swallow hirundo rustica wing and tail feathers
PLOS ONE, 2015Co-Authors: Gergely Osvath, Jose Miguel Aparicio, Lőrinc Bărbos, Piotr Matyjasiak, Diego Rubolini, Nicola Saino, Csongor I Vagasi, Orsolya Vincze, Anders Pape MollerAbstract:Sexual selection and Aerodynamic Forces affecting structural properties of the flight feathers of birds are poorly understood. Here, we compared the structural features of the innermost primary wing feather (P1) and the sexually dimorphic outermost (Ta6) and monomorphic second outermost (Ta5) tail feathers of barn swallows (Hirundo rustica) from a Romanian population to investigate how sexual selection and resistance to Aerodynamic Forces affect structural differences among these feathers. Furthermore, we compared structural properties of Ta6 of barn swallows from six European populations. Finally, we determined the relationship between feather growth bars width (GBW) and the structural properties of tail feathers. The structure of P1 indicates strong resistance against Aerodynamic Forces, while the narrow rachis, low vane density and low bending stiffness of tail feathers suggest reduced resistance against airflow. The highly elongated Ta6 is characterized by structural modifications such as large rachis width and increased barbule density in relation to the less elongated Ta5, which can be explained by increased length and/or high Aerodynamic Forces acting at the leading tail edge. However, these changes in Ta6 structure do not allow for full compensation of elongation, as reflected by the reduced bending stiffness of Ta6. Ta6 elongation in males resulted in feathers with reduced resistance, as shown by the low barb density and reduced bending stiffness compared to females. The inconsistency in sexual dimorphism and in change in quality traits of Ta6 among six European populations shows that multiple factors may contribute to shaping population differences. In general, the difference in quality traits between tail feathers cannot be explained by the GBW of feathers. Our results show that the material and structural properties of wing and tail feathers of barn swallows change as a result of Aerodynamic Forces and sexual selection, although the result of these changes can be contrasting.