【作者】 岳巍澎；

【导师】 郭婷婷；

【作者基本信息】 东北电力大学 ， 动力机械及工程， 2011， 硕士

【摘要】 由于当前国际能源紧缺以及风电站大规模建立,大型风场存在占地面积大,风力机间相互干扰严重等缺点。因此,如何充分、高效地开发利用风能资源及经济、合理减小风电场占地面积将成为今后值得关注的重要课题。风场中风力机布置以及由风力机之间尾流互扰,会造成的单机功率损失甚至影响整个风场风能利用效率及输出功率。本文运用Fluent对风力机叶片、整机以及双机组不同布置时的气动性能进行数值研究,具有重要的应用价值和理论意义。首先:利用FLUENT,采用分离隐式求解器,湍流模型选择SSTk ?ω模型,离散方式为二阶迎风格式,压力-速度耦合采用SIMPLEC。对1.2MW风力机旋转风轮流场进行了数值模拟。比较设计转速为18.44rpm工况下风轮与单叶片流场;三叶片风轮与相同叶片单叶片、双叶片以及四叶片的输出功率、湍动能。通过分析风轮旋转对叶片间流动的影响表明:旋转上游叶片在转动过程中会发生附着涡的脱落,下游叶片的流场环境发生变化,其对叶片转矩及输出功率影响很大。其次:着重介绍基础尾流理论以及一系列推导过程,结合尾流理论分别对单机尾流气动性能进行分析,通过比较单机风力机下风向流场分布和尾流模型计算结果,验证数值模拟合理性。之后对两台串列、并列及错列布置的风力机进行了数值模拟。比较各种布置方式的输出功率、流场分布,对风力机间相互影响及互扰损失进行分析。得出结论:单风力机流场呈发散状,由于风力机顺时针旋转,整机尾流偏向叶片旋转下游方向。串列布置时,下风向叶轮对上风向机组发散状尾流有收敛作用,下风向机组受上游尾流影响较大,功率明显降低;并列及错列时被干扰机组受参考机组尾流挤压,但功率受影响较小。最后:对固定距离的两个风力机组的不同排列情况进行数值模拟。通过比较单机及各种布置角度的输出功率、流场分布,对风力机间相互影响及互扰造成功率损失进行分析。结果表明:随着风向发生变化,下风向风力机移出上风向阴影,其功率逐渐增加。机组间距离应与当地盛行风向变化范围成正比。更多还原

【Abstract】 Because of energy-deficiency in the international community, large-scale wind power plants are being built in nowadays. There are many problem in wind power plants such as covering too large area and mutual interference between each other. Therefore, how to fully and effectively use the energy resources and reduce land occupation must be concerned as the important topic for future study. Power loss of single turbine and even wind energy equipment utilization efficiency of wind power plant were caused by array in wind power plants and the wake interference between wind turbines. It is not only the oretically important, but has practical value to study the wake aerodynamic of the wind turbine. Blades, single wind turbine and double roter of different arrangements have been simulated using the Fluent 6.3.First,numerical simulation is conduced with software FLUENT. Pressure based, segregated, steady implicit are set in the solver. Turbulence model is SST k ?ω. Pressure-velocity coupling scheme is SIMPLEC. Discretization scheme is Second Order Upwind scheme. Power output and turbulent kinetic energy were compared with different numbers of rotating wind turbine and with single blade’s and rotating blades. Computational results showed that the attaches vortex shedding from upper rotating blades was occurred during the operation,which lead to the change under lower blades environments and has great influence on total moment and power output.Secondldy, the numerical simulation is verified for its feasibility by comparing the aerodynamic performance of CFD model and wake model. The aerodynamic interaction between two rotors in both co-axial, arrangement in parallel and stagger arrangement and offset configurations has been simulated. Comparison of different location of both turbines simulation results were used for the analysis of wake interaction and velocity deficit in downstream wind direction. To reach the conclusion, the wake outlet is divergent shape. The wake of wind turbine is bias towards blade rotation downstream direction. Downstream turbine makes the upstream diverging wake to be convergence under co-axial wind conditions, and the output of downstream turbine is affected by upstream wake. Arrangement in parallel and stagger arrangement results in little power loss although their flow field were extruded by the wake effect of the reference turbine.Finally, comparison of different location of both turbines simulation results was used for the analysis of wake interaction and velocity deficit in downstream wind direction. The results showed that downstream turbine makes the upstream diverging wake to be convergence under co-axial wind conditions, and the output of downstream turbine is affected by upstream wake. As the wind direction change, down-stream turbines is removed from up-stream wind wake shadows, and the output power increases. The distance between the units should be proportional to the local prevailing winds range.更多还原