Analysis Of Wake Flow Fields And Aerodynamic Performance For Horizontal-axis Wind Turbine

Wind power, as a clean and renewable energy, has been received widespread concern in each country. With the rapid development of modern industry, development of the wind power has become an important measure to solve the energy crisis, environmental issues and sustainable economic development. In recent years, however, with the rapid development of offshore wind power, wind turbine large scale has become the mainstream of development of the wind turbine. Increasing the length of the wind turbine blade result in the wake flow is more complex, it is difficult to predict the aerodynamic performance.In this thesis, aiming at a commercial1.5MW standard grades of horizontal axis wind turbine was studied. Through the establishment three-dimensional modeling of the horizontal axis wind turbine and wind wheel numerical model, in three different wind conditions and wake on the wind wheel dynamic properties were described and compared, and the value of monitoring the residual values and torque in the process of calculation. In order to better describe the wind wheel is rotating in3D Aerodynamic Characteristics, were analyzed respectively on the blade suction surface and pressure on the surface of the pressure field and velocity field, and select the pressure and speed of three section along the blade spanwise is discussed.Based on the theory of similarity, the1.5MW horizontal axis wind turbine with various parameters of wind turbine aerodynamic similarity criterion and functional relation of shrinkage ratio, establishes the corresponding numerical model. It has the same Reynolds number and tip speed ratio with the large model, through the analysis of the blades and in the wake of the pressure, velocity and other parameters, it will verify of the aerodynamic similarity criterion and function relationship in practical application is correct. Finally, we would be velocity values in different section by using the Fluent software calculated in the flow field were compared with the experimental measurements, it will verify the correctness of model and rationality of the experiment.Results show that when the impeller is rotating, the surface pressure of the blade near the leading edge with high pressure, and low pressure areas on the suction surface near the leading edge; with the increase of flow velocity, the pressure difference on blade pressure surface and the suction surface at the leading edge is greater; By contrast, when keeping the Reynolds number and the tip speed is constant, with the same wind speed two model on the blade pressure and velocity distribution trends are the same, there was not much difference; The results will be compared with the experimental values can be obtained in the wind wheel downstream3D between measured and simulated values fit better.With the increase of axial distance, measured and simulated values consistent trend overall development, there was more obvious differences (mainly refers to the section wind wheel swept area). I hope that through this numerical study on the horizontal axis wind turbine can provide a foundation for the research work and dynamics simulation of wake wind, and hope that the researches ideas in this thesis can do horizontal axis wind turbine numerical simulation study of the people play a certain reference role for the follow-up.