The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Seyed Rasoul Varedi - One of the best experts on this subject based on the ideXlab platform.
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Starting Torque improvement using j shaped straight bladed darrieus vertical axis wind turbine by means of numerical simulation
Renewable Energy, 2016Co-Authors: Mahdi Zamani, Mohammad Javad Maghrebi, Seyed Rasoul VarediAbstract:In this study a 3 kW straight–bladed Darrieus type Vertical Axis Wind Turbine (VAWT) is investigated numerically using OpenFOAM computational fluid dynamic package. The newly proposed J-Shaped profile is used as the blade airfoil in the simulation. The J-Shaped profile is designed by means of eliminating a fraction of pressure side of Du 06-W-200 airfoil. The main purpose of this investigation is the improvement of the VAWT Starting Torque using J-shaped profile. The power curves for both conventional and J-shaped profiles are calculated and the Torque variation is obtained at different azimuth angles. In addition, the vorticity and pressure field surrounding the wind turbine is presented. The results indicate that the performance of turbine is optimized for J-shaped profile which eliminates the pressure side of airfoil from the maximum thickness toward the trailing edge. Moreover, by employing this J-Shaped profile, the wind turbine performance is intensified TSRs and self-Starting of turbine is improved.
Mahdi Zamani - One of the best experts on this subject based on the ideXlab platform.
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Starting Torque improvement using j shaped straight bladed darrieus vertical axis wind turbine by means of numerical simulation
Renewable Energy, 2016Co-Authors: Mahdi Zamani, Mohammad Javad Maghrebi, Seyed Rasoul VarediAbstract:In this study a 3 kW straight–bladed Darrieus type Vertical Axis Wind Turbine (VAWT) is investigated numerically using OpenFOAM computational fluid dynamic package. The newly proposed J-Shaped profile is used as the blade airfoil in the simulation. The J-Shaped profile is designed by means of eliminating a fraction of pressure side of Du 06-W-200 airfoil. The main purpose of this investigation is the improvement of the VAWT Starting Torque using J-shaped profile. The power curves for both conventional and J-shaped profiles are calculated and the Torque variation is obtained at different azimuth angles. In addition, the vorticity and pressure field surrounding the wind turbine is presented. The results indicate that the performance of turbine is optimized for J-shaped profile which eliminates the pressure side of airfoil from the maximum thickness toward the trailing edge. Moreover, by employing this J-Shaped profile, the wind turbine performance is intensified TSRs and self-Starting of turbine is improved.
Mohammad Javad Maghrebi - One of the best experts on this subject based on the ideXlab platform.
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Starting Torque improvement using j shaped straight bladed darrieus vertical axis wind turbine by means of numerical simulation
Renewable Energy, 2016Co-Authors: Mahdi Zamani, Mohammad Javad Maghrebi, Seyed Rasoul VarediAbstract:In this study a 3 kW straight–bladed Darrieus type Vertical Axis Wind Turbine (VAWT) is investigated numerically using OpenFOAM computational fluid dynamic package. The newly proposed J-Shaped profile is used as the blade airfoil in the simulation. The J-Shaped profile is designed by means of eliminating a fraction of pressure side of Du 06-W-200 airfoil. The main purpose of this investigation is the improvement of the VAWT Starting Torque using J-shaped profile. The power curves for both conventional and J-shaped profiles are calculated and the Torque variation is obtained at different azimuth angles. In addition, the vorticity and pressure field surrounding the wind turbine is presented. The results indicate that the performance of turbine is optimized for J-shaped profile which eliminates the pressure side of airfoil from the maximum thickness toward the trailing edge. Moreover, by employing this J-Shaped profile, the wind turbine performance is intensified TSRs and self-Starting of turbine is improved.
G.h. Jang - One of the best experts on this subject based on the ideXlab platform.
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Dual winding method of a BLDC motor for large Starting Torque and high speed
IEEE Transactions on Magnetics, 2005Co-Authors: G.h. JangAbstract:This paper presents a novel winding method and its inverter circuit to drive a brushless dc (BLDC) motor to high speed with large Starting Torque. The proposed winding coils are composed of dual windings, i.e., main and auxiliary windings, and the proposed inverter circuit has nine switches. In the Starting period, it energizes both main and auxiliary windings in parallel connection to generate large Starting Torque. After the motor is accelerated, the proposed inverter circuit is automatically switched to energize main winding, which generates small back-electromotive force, to reach high speed. The proposed method is applied to the spindle motor of a hard disk drive and its effectiveness is verified through experiment.
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a bipolar Starting and unipolar running method to drive a hard disk drive spindle motor at high speed with large Starting Torque
Asia-Pacific Magnetic Recording Conference, 2005Co-Authors: G.h. JangAbstract:This paper presents a method to drive a hard disk drive (HDD) spindle motor at high speed with large Starting Torque by utilizing a bipolar-Starting and unipolar-running algorithm. It proposes a novel inverter circuit to switch from bipolar to unipolar drive, or vice versa. It also develops a digital signal processor (DSP)-based brushless dc (BLDC) motor controller not only to drive the BLDC motor with the bipolar or unipolar method, but also to switch from one method to the other at any speed. Torque-speed-current curves of a BLDC motor driven by bipolar or unipolar method are investigated experimentally, and the effectiveness of the proposed method is also verified by using the developed controller experimentally. This research shows that the proposed method starts the BLDC motor with large Starting Torque that can be obtained by a bipolar drive, and it runs the BLDC motor at high speed that can be driven by unipolar drive.
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A bipolar-Starting and unipolar-running method to drive a brushless DC motor in high speed with large Starting Torque
Digest of INTERMAG 2003. International Magnetics Conference (Cat. No.03CH37401), 2003Co-Authors: G.h. JangAbstract:In this paper, we have discussed a bipolar-Starting and unipolar-running method to drive a brushless DC motor in high speed with large Starting Torque and verified the proposed algorithm experimentally by developing a DSP-based controller to drive a BLDC motor with various driving methods.
Jaehak Choi - One of the best experts on this subject based on the ideXlab platform.
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the rewritable effects of bonded magnet for large Starting Torque and high efficiency in the small power single phase written pole motor
Journal of Applied Physics, 2009Co-Authors: Jaehak ChoiAbstract:This paper presents a single-phase written pole motor using a bonded ring magnet for the small power home application. The motor has an exciter pole structure inside the stator and hybrid characteristics of an induction motor and permanent magnet motor. The design parameters and operating characteristics of the hybrid concept motor are investigated to increase Starting Torque and efficiency, which is most important for the small power home application. Larger Starting Torque and higher efficiency than those of the conventional induction motor could be obtained by using the rewritable characteristics of bonded magnet on the Starting and running conditions.