A design and optimization method for matching the torque of the wind turbines

Abstract

Due to copyright restrictions, the access to the full text of this article is only available via subscription.An aerodynamic shape optimization method for a horizontal axis wind turbine is developed and verified through experimentation with a laboratory-scale wind turbine. Our method is based on matching the rotor's and the coupled generator's torque. Prior to shape optimization, an initial rotor design is established with a hybrid use of Schmitz and blade element momentum theories. The experimental verification of the developed method is conducted with a small-scale wind turbine; thus, the operating Reynolds number is one order of magnitude lower than large-scale wind turbines. Therefore, a high-lift low-Re airfoil, namely, SG6043, is selected for the blade along the whole span. The shape is optimized by determining the optimum chord and cumulative pitch angle distributions by manipulating the tapering and twisting of the blade. The objective of the optimization is to maximize the turbine's power coefficient Cp , while maintaining the torque equal to that of the generator. The generator's characteristics are found through experimentations which are conducted apart from the wind tunnel experiments. During the optimization process, the local aerodynamic forces on the blade are calculated by interfacing the optimization program with XFOIL; thus, the torque and power can be calculated for the rotor at each iteration step. The optimized turbine performance is evaluated under a design and off-design operating condition. The performance verification experiments are carried out in the wind tunnel with a specially designed setup. A comparison of the measured and computed performance shows good agreement

Influence of airfoil trailing edge on blade design and machining of small wind turbine

“…(9) By using formula (7) , the C i formula (10) for the chord length of the blade element section airfoil can be obtained, and the dip angle φ formula (11) for the blade element section airfoil can be obtained by simultaneous (7) and (8) . The results are as follows:…”

“…In reference [6] , the blade element momentum method is used to simulate the wind turbine, and various factors are considered in the design, and the variation trend of power coefficient with blade number and tip speed ratio is studied. A method for aerodynamic shape optimization of horizontal axis wind turbine based on torque matching between rotor and coupled generator is presented in reference [7] . Reference [8] a low Reno number airfoil is designed for a small horizontal axis wind turbine to achieve better start up and low wind speed characteristics, the aerodynamic characteristics of the improved airfoil (AF300) are verified in an open-circuit wind tunnel.…”

Small Wind Turbine Blade Design and Optimization

“…They used E-glass and polyester resin in the blade design. Al-Abadi et al [5] developed an aerodynamic shape optimization method for a horizontal axis wind turbine. They matched the torques produced by the rotor and the coupled generator and optimized the blade shape.…”