Studies on Performance of Distributed Vertical Axis Wind Turbine under Building Turbulence

As a part of the new energy development trend,distributed power generation may fully utilize a variety of decentralized energy sources.Buildings close to the installation location,besides,may have a considerable impact on the wind turbines’operation.Using a combined vertical axis wind turbine with an S-shaped lift outer blade and-shaped drag inner blade,this paper investigates how a novel type of upstream wall interacts with the incident wind at various speeds,the influence region of the turbulent vortex,and performance variation.The results demonstrate that the building’s turbulence affects the wind’s horizontal and vertical direction,as well as its speed,in downstreamplaces.The wall’s effect on wind speed changing in the downstreamarea is thoroughly investigated.It turns out that while choosing an installation location,disturbing flow areas or low disturbing flow zones should be avoided to have the least impact on wind turbine performance.

屋顶安装型风力机塔架风振反应分析

为了研究屋顶安装型风力机塔架在风荷载作用下的动力性能,对该塔架进行风振时程反应分析.建立考虑叶片传至塔架作用力的塔架振动方程,采用引入快速傅里叶变换(FFT)技术的谐波叠加法分别模拟得到叶片和塔架的风速时程,利用叶素理论计算叶片传至塔架作用力.研究屋顶集风效应和叶片旋转对此类风力机塔架风振反应的影响.结果表明考虑屋顶集风效应后塔架的风振反应有一定增强;叶片旋转情况下塔架位移和弯矩显著增加.

不同建筑顶部风力机安装位置的数值模拟

基于CFD方法对同一风场下不同屋顶形状的建筑模型进行数值模拟,引入平衡大气边界层和地表粗糙度等影响条件,对比分析5个风向角下6种屋顶结构对应的流场变化,根据25个参考位置的风速增长系数及湍流强度的变化情况来判断理想的风力机安装位置。结果表明:模拟平衡大气边界时,利用流场边界条件以及控制方程参数的修正能实现整个流场入流参数的水平稳定;不同屋顶形状的建筑对应的最佳安装位置在不同的风向下差异较大,在正面迎风的情况下,以流线型为主的拱形和球顶在中心位置处安装风力机能获得1.13倍的风速增长;在所有的迎风情况中,侧面45°迎风中以球顶中心处安装最佳,理论上能提高52.1%的发电效率。