几种典型状况下垂直轴风力机气动特性及流场分析

发布时间：2018-03-14 19:26

  本文选题：垂直轴风力机　切入点：深度失速　出处：《兰州理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：风资源作为一种可再生的清洁能源,已经得到了全世界的广泛关注。在我国风能已是继水电和火电之后的第三大能源。垂直轴风力机是典型的小型风力机,它具有不用对风向,结构简单,可以使用于住宅小区等不可替代的优势,受到了社会的广泛关注。但是为了进一步提高垂直轴风力机的风能利用率,还仍需做大量的研究。本文以H型垂直轴风力机为研究对象,对几种典型状况下的垂直轴风力机气动特性及流场做了进一步的研究工作。 H型垂直轴风力机属于升力型风力机。受其结构和使用环境的影响,H型垂直轴风力机一般运行在风力机的低风速区,而且上风轮叶片产生的尾涡效果直接作用于下风轮的叶片上,同时还有叶尖涡的影响,所以整个H型垂直轴风力机的内流场和风轮附近的流场是非常复杂的。因此,本文主要从自主研发的翼型出发,分别对H型垂直轴风力机的2D,3D模型进行数值模拟计算,分析了自主研发翼型在深度失速状态下的升阻性能；低风速下的H型垂直轴风力机的性能；并探讨了转动惯量和不同的叶尖小翼对H型垂直轴风力机性能的影响；最后分析叶片数对H型垂直轴风力机有弯度叶片的两种不同安装方式的影响；其主要内容包括： 1.采用数值模拟的方法,分别选用URANS,LES,DES三种不同的湍流模型对自主研发的翼型进行非定常的模拟计算,并和实验数据进行对比。探讨了三种不同的湍流模型在研究翼型深度失速时对升阻力预测的区别,分析出不同模型的优势,便于后续模拟计算时湍流模型的选取。结论显示：自主研发的翼型深度失速时的最大攻角为30°,相比原模型的深度失速攻角23°有明显的提高；在翼型的攻角小于最大深度失速攻角的时候,使用三种湍流模型计算的升力和阻力性能相差不大,且和原模型的试验值比较接近；在翼型发生深度失速后,DES湍流模型的模拟结果不仅具有一定的可靠性,而且能够捕捉到翼型周围存在的涡流状况； 2.以自主研发的H型垂直轴风力机为研究对象,采用数值模拟的研究方法,分析了低风速下H型垂直轴风力机的气动性能和三维效应特征。分析结果表明：低风速区域,保持叶尖速比不变,改变风轮转速或改变来流风速,对H型垂直轴风力机的性能影响差别很大,故在设计和选用H型垂直轴风力机时,在保证合理叶尖速比的同时,还要注意实际风速和转速的情况；在数值模拟时,合理设定风速和转速有利于模拟结果的可靠性；内流场的作用影响模拟结果； 3.以翼型NACA0012的单叶片H型垂直轴风力机为研究对象,采用数值模拟的研究方法,分析了叶片两端未安装叶尖小翼和安装三种不同的叶尖小翼对H型垂直轴风力机叶片的表面压力分布和叶尖涡的影响以及气动性能的影响。结果表明：安装小翼均可提高H型垂直轴风力机的最大转矩系数,其中安装Winglet还提高H型垂直轴风力机启动力矩；增加叶尖小翼均对消除叶尖涡有利；H型垂直轴风力机叶片两端安装Winglet较其他两种小翼效果好；同时安装小翼对H型垂直轴风力机的升阻系数比影响不大,但在0°方位角位置安装Winglet提高了升阻系数比值；V型小翼和winglet小翼对法向力系数和切向力系数的影响较大,特别是winglet小翼；通过优化winglet小翼的几何参数和安装角度,有提高H型垂直轴风力机整体性能的潜力。 4.垂直轴风力机是旋转机械,转动惯量对其主要的气动性能(功率,功率系数,转矩,转矩系数等)有一定的影响。本文基于双向多流管理论和转动惯量的动能定理并利用Matlab编程,以翼型为NACA0018的H型垂直轴风力机为研究对象,分析了转动惯量对H型垂直轴风力机性能的影响。分析发现：转动惯量的小范围变化对其最大输出功率系数影响不大,但较小转动惯量的风力机需要较大的风速才可以达到最大输出功率；在达到最大输出功率以前,较小转动惯量的风力机具有相对较大的功率系数、转矩系数和输出功率；随着风速的增大,转动惯量较小的风力机功率系数、转矩系数、转矩波动较大； 5.采用非对称翼型的H型垂直垂直轴风力机有弯度的叶片,叶片有两种安装方式,一种是弯度向里,另一种是弯度向外。采用数值模拟的方法,主要探讨了不同叶片数对上述有弯度叶片的两种安装方式的影响。分析结果表明：采用非对称翼型的H型垂直轴风力机有弯度叶片正置安装和反置安装,叶片反置安装的风力机在方位角为90°的时候,其背风面和迎风面的压力变化很大,而在0°,180°和270°方位角下,两种安装方式差别不大；随着叶片数的增加,叶片反置安装的风力机力矩系数要小于叶片正置的风力机,且叶片反置安装的风力机所产生的湍流度要高于叶片正置的情况；在低叶尖速比区域,叶片反置的风力机的功率系数要大于叶片正置的风力机,其最大功率也比较大；而在高叶尖速比区域,叶片反置的风力机的功率系数要小于叶片正置的风力机。
[Abstract]:The wind resources as a renewable and clean energy, has been widespread concern in the world. In China is the third largest wind energy after hydropower and thermal power. The vertical axis wind turbine is a typical small wind turbine, it has no need of direction, simple structure, can be used in residential areas can not be replaced the advantage of a widespread concern in society. But in order to further improve the vertical axis wind turbine wind energy utilization rate, still need to do a lot of research. In this paper, the H type vertical axis wind turbine as the research object, the vertical axis wind turbine gas for several typical conditions of dynamic characteristics and flow field to do further research work.
H type vertical axis wind turbine belongs to lift type wind turbine. Affected by the structure and use of the environment, the H type vertical axis wind turbine operating at low wind speed of wind turbine, vortex effect and wind wheel blade have direct effects on the wind wheel blade, as well as the influence of tip vortex, so the whole H type vertical axis wind turbine flow field and the flow field near the wind wheel is very complex. Therefore, this article from the independent research and development of the airfoil, respectively for H type vertical axis wind turbine 2D, 3D model for numerical simulation, the aerodynamic performance of independent research and development in depth of airfoil stall condition analysis; the performance of H type vertical axis wind turbine under low wind speed; and discusses the moment of inertia and the different tip vane effect on H type vertical axis wind turbine performance analysis; finally, the number of leaves on H type vertical axis wind turbine has two kinds of blade camber The main contents of the installation are as follows:
1. by the method of numerical simulation, respectively by URANS, LES, DES airfoil three different turbulence models on independent research and development of unsteady simulation often, and compared with the experimental data. Three kinds of turbulence models in the study of the difference between deep stall airfoil lift and drag prediction, analysis of different the advantages of the model, selected for subsequent simulation of turbulence model. The conclusion shows that the maximum angle of independent research and development of the airfoil stall the depth is 30 degrees, compared to the depth of the stall angle of attack of the original model of 23 degree have been significantly improved; in the angle of attack is less than the maximum depth when the airfoil stall angle, lift and drag performance calculation using three a turbulence model is small, and the original model and experimental values are close in depth; airfoil stall, simulation results of DES turbulence model not only has a certain reliability, but also can The eddy current status around the airfoil was captured.
2.浠ヨ嚜涓荤爺鍙戠殑H鍨嬪瀭鐩磋酱椋庡姏鏈轰负鐮旂┒瀵硅薄,閲囩敤鏁板，

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