风力机多层阻尼叶片抑颤性能分析

发布时间：2018-06-20 16:29

本文选题：风力机 + 叶片　；参考：《太原科技大学》2017年硕士论文

【摘要】：风能作为绿色洁净的新能源,愈加受到全球各个国家的青睐和看重。我国风力机装机容量逐年增加,且1.5MW和2MW成为主流,所占份额越来越大。而这两种机型的叶片长度都达到30m以上。风力发电愈加追求单位发电成本,导致叶片向着细长化发展。叶片在惯性力、重力和气动载荷共同作用下,很容易发生严重变形和颤振,进而产生疲劳裂纹破坏。因此,控制大型风力机叶片颤振已成为现代风力机设计的重要部分。阻尼减振减噪技术是抑颤的有效方法之一。该技术是利用阻尼材料受交变应力作用时,分子链之间发生滑移且不可恢复,这种滑移将振动体的机械能转变为热能或者其它可以耗散的能量,从而起到减振及降噪的目的。本文将多层阻尼结构应用在叶片中,来抑制叶片振动。本文首先对叶片抑颤和阻尼结构研究背景进行了综述;简要说明了风力机机组组成和叶片主要参数,以某国产1.5MW叶片为例,建立三维模型并进行了模态分析;依据空气动力学推导出叶片升、阻力和叶片运动微分方程,分析了叶片发生颤振的条件;对阻尼附加结构和其耗能原理进行了阐述,并推导了多层弱约束阻尼结构和多层约束阻尼结构的损耗因子;对自由阻尼叶片和多层弱约束阻尼叶片、单层约束阻尼叶片和多层约束阻尼叶片两组叶片进行了模态分析对比和动力学分析对比,结果显示,多层阻尼叶片比单层阻尼叶片具有更好的抑颤性能。
[Abstract]:Wind energy as a green and clean new energy, more and more favored and valued by all countries around the world. The installed capacity of wind turbines in China increases year by year, and 1.5MW and 2MW become the mainstream, which accounts for more and more. The blade length of these two models is more than 30 m. Wind power increasingly pursues unit power cost, leading to the development of slender blade. Under the combined action of inertial force gravity and aerodynamic load the blade is prone to serious deformation and flutter resulting in fatigue crack failure. Therefore, controlling the flutter of large wind turbine blade has become an important part of modern wind turbine design. Damping vibration and noise reduction technology is one of the effective methods of vibration suppression. In this technique, when damping materials are subjected to alternating stress, the molecular chains slip and cannot be recovered. This slip can transform the mechanical energy of the vibrating body into heat energy or other energy that can be dissipated, so as to reduce vibration and noise. In this paper, the multilayer damping structure is applied to the blade to suppress the blade vibration. In this paper, firstly, the research background of blade vibration suppression and damping structure is summarized, and the composition and main parameters of wind turbine unit are briefly explained. Taking a domestic 1.5 MW blade as an example, a three-dimensional model is established and modal analysis is carried out. According to aerodynamics, the differential equations of blade lift, resistance and blade motion are derived, and the conditions of blade flutter are analyzed, and the damping additional structure and its energy dissipation principle are described. The loss factors of multi-layer weakly constrained damping structure and multi-layer constrained damping structure are derived, and the free damping blades and multi-layer weakly constrained damping blades are obtained. The modal analysis and dynamic analysis of two groups of blades with single-layer constrained damping and multi-layer constrained damping are carried out. The results show that the multi-layer damping blade has better vibration suppression performance than the single-layer damping blade.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB535.1;TK83

【参考文献】