Numerical Simulation Study On Wake Interaction Of The Horizontal-axis Wind Turbines

Along with the growing shortage of traditional non-renewable energy and a series of problems brought by it, as well as meeting the need of rapid development of the society, people pay more attention to the exploitation of clean energy and renewable utilization of resources, thus wind energy come into sight by virtue of its unique advantages. In the wind farm, the layout of the wind turbine is particularly important as the existence of wake effect. Therefore, study the characteristics of multiple sets of wind turbine wake interference to grasp the mutual influence law of the wind turbine wake characteristics, so as to minimize or avoid wake interference effect among the wind turbines, which is important significance to increase the output power and efficiency of wind farm overall.In order to have a in-depth understanding of wake interaction among the wind turbines, this dissertation has used the fluid software Fluent to proceed full3D numerical simulation for wind turbine entire machine, basing on10kW small wind turbine as the main research object. This dissertation has mainly completed the following work.With the purpose of modeling a3D entity wind turbine, appropriate blade core parameters have been determined, and aerofoil software Profili,3D modeling software UGNX7.0and grid software ICEM have been used to model blade, hub, cabin and tower respectively based on the combined modeling method, and then assembled every part model. It has laid a foundation for subsequent3D aerodynamic characteristics of wind turbine entire machine research and wake interference characteristics analysis.RANS method has been used to proceed a3D numerical simulation analysis for single set of wind turbine, so as to understand aerodynamic characteristics of the flow field. The influence of the cabin and tower have been considered in the actual simulation. To make use of wind turbine3D entity model, and use Fluent to proceed a3D numerical simulation analysis for single set of wind turbine entire machine, and calculate the power output of wind turbine under different working conditions, so as to get the relation curve between the tip speed ratio and power coefficient. Through the comparison between the relation curve and wind tunnel experiment curve, the reliability to the wind turbine blade optimization design and3D entity modeling method and the numerical simulation method have been approved, which have laid a foundation for subsequent research of wake characteristics interaction of the multiple sets of wind turbine.Based on3D aerodynamic characteristics numerical simulation for single set of wind turbine, the wake interference characteristics of the multiple sets of wind turbine has been studied. The tower height difference among wind turbines and the arrangement of the wind turbine have been respectively disscussed to learn wind turbine wake interaction. Research shows that the power output of the downstream wind turbine lose most when the tower height of two sets of wind turbine is the same. In addition, the staggered grid arrangement has been much better than the straight line grid for the little change of prevailing wind direction. Based on the staggered grid arrangement, utilize reasonably of the layout of the tower height difference, and minimize wake interference effect among the wind turbines, so as to increase the output power and efficiency of wind farm overall. The wind turbine output power can be used to have a quantitative analysis on simulation results, which can be effectively applied to a wind farm layout design, site evaluation, and power output prediction in the future.