垂直轴风力机的结构分析及设计优化

发布时间：2018-01-12 12:35

本文关键词：垂直轴风力机的结构分析及设计优化　出处：《华北电力大学》2015年硕士论文　论文类型：学位论文

【摘要】：全球化石能源燃料的过度消耗以及人类生存环境的逐日恶化,使得新型无污染能源成为世界各国高度关注的焦点。风能,作为新型无污染能源的典型代表,在开发和利用方面显得尤为迅猛。我国作为典型的发展中大国,风力发电在我国的状况更是如此,最近几年,我国在政策法规及经济技术上大力推动新型能源的开发利用,但是,作为一个后续利用新型能源的发展中大国,我国的风力发电技术还是远远地落后于其它发达国家的,其中,主要的表现就是风机叶片的研究。本文通过理论分析与有限元数值模拟相结合的方法,对一个应用于项目实验中的垂直轴风力机进行相关研究,使仿真计算结果更加逼近实际工况,达到更加准确的计算结果,主要的工作和成果有：1)介绍了世界各国在垂直轴风力机方面的研究背景及研究成果,通过对其设计理论、流管模型以及空气动力学在其中的运用的详细讲述,明确了其运行状态及动力来源,并运用转矩公式推导了其转动力矩的计算公式。2)通过运用流场分析软件FLUENT,对所研究叶片的建模分析,计算得到了此种叶片翼型的气动性能参数以及叶片表面的风压、风速云图等。研究表明：此种风力机叶片的升阻比较高,空气动力学性能较好。3)通过对此种翼型的五叶片MRF模型的建立,计算得到了风机周围区域的流场情况,在以后的实际风场的压力场变化研究上,奠定了更加扎实的基础。4)详细阐述了在流场计算软件FLUENT中模拟计算风机叶片表面对应节点处的风压,以及以EXCEL表格的形式进行输出,然后再运用MATLB软件进行数据拟合,最后倒入有限元软件ANSYS中的具体操作过程及处理方式。在风载作用的计算上此种方式的计算更为精确。通过最佳攻角状态下叶片结构表面的力学结构分析可知：承受风载压力最大的位置是翼型叶片同风机支撑的连接部位,叶尖处较小,基本呈对称分布。在做叶片结构设计时可以参考上述结论,对受力较大的叶片连接点处重点加强,对受力较小的位置适当减少材料。同时本文还进行了叶片的模态分析,得到了前6阶的模态振型图及相关数据,分析得出：该叶片不存在产生共振的可能性,符合设计要求。5)通过ANSYS软件的应用,对塔架的稳定性及振动特性进行分析。稳定性的分析,得到了塔架的屈曲临界弯矩,并确定了塔架具有很小的失稳倾向性；模态的分析,确定了塔架、叶片的各阶固有频率,机组不会出现共振现象。上述所做的工作,旨在能够更好地实现对风机机组结构的力学性能分析,更加确切地,真实地还原风力机机组在运行中所面临的工作力学问题,从而得到更精确的结构设计,避免不必要的资源损失,同时也希望能够为垂直轴风力机机组结构力学性能分析起到一定的经验价值和借鉴作用。
[Abstract]:The fossil energy fuel excessive consumption and human living environment is deteriorating day by day, the new pollution-free energy has become the focus of attention of all countries in the world. Wind energy, as a typical kind of non polluting energy, in the development and use of it is particularly rapid. China is a typical developing country, wind power generation in China the situation is so, in recent years, China's policies and regulations in the economic and technology vigorously promote the development and utilization of new energy. However, as a big developing country with a subsequent use of new energy, China's wind power technology is still far behind other developed countries, the main performance is the wind turbine blade research. Through theoretical analysis and finite element numerical simulation method combining the related research of vertical axis wind turbine on a project used in experiments, the simulation Results more close to actual conditions, to achieve more accurate results, the main work and results are as follows: 1) introduces the research background and research achievements in the vertical axis wind turbine the world, based on the design theory, detailed flow using tube model and aerodynamic in the clear, the the running state and the power source, and the use of torque is deduced the torque calculation formula of.2) by using flow analysis software FLUENT, analysis of the modeling on leaves, calculated the blade aerodynamic performance parameters and wind pressure on the surface of leaves, the wind speed contour. The study shows that the lift drag wind turbine the blade is relatively high, the aerodynamic performance of.3 is better) by establishing the MRF model of this kind of five blade airfoil, obtained the flow field around the area of the fan after the actual calculation. The changes of the pressure field of wind field on the foundation of.4 more solid) describes the simulation calculation of air pressure of fan blade surface corresponding to the nodes in the FLUENT software in the field, as well as EXCEL form in the form of output, and then use the MATLB software for data fitting, and finally into the finite element software ANSYS the specific operation process and treatment. In the calculation of wind load calculation in this way is more accurate. The mechanical structure of the surface structure of leaves under the condition of optimum angle of attack. The analysis shows: the position of the maximum pressure under wind load is connected with the airfoil fan support, at the tip of small, basically symmetrical distribution. Refer to the above conclusion in blade structure design, strengthen the blade large stress at the connection point of focus, smaller stress position appropriate to reduce the material. At the same time this paper The modal analysis of blade, the first 6 order modal graph and the related data analysis shows that the blade does not exist the possibility of resonance, meet the design requirements of.5) by the application of ANSYS software, analyzed the stability and vibration characteristics of the tower. The stability analysis, the critical moment of the tower. And the tower has a stable tendency of very small loss; modal analysis, to determine the tower, the natural frequency of the blade, the unit will not appear resonance. The work mentioned above, in order to better achieve the mechanical properties of the wind machine group structure analysis, more precisely, restore the true work the mechanical problems facing the wind turbine unit in operation, so as to obtain more accurate structural design, to avoid unnecessary loss of resources, also hope to be able to analyze performance of vertical axis wind turbine generator mechanical structure up To a certain value of experience and reference.

【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM315

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