建筑物群内屋顶形状对屋顶风力机微观选址的影响

Influence of Roof Shape on Micrositing of Rooftop Wind Turbine in the Building Group

以符合城市粗糙大气边界层的速度剖面为入口边界条件,采用Realizable k-ε湍流模型对北方地区常见的、顺列布置的斜屋顶、金字塔屋顶、三角形屋顶及平屋顶建筑物群顶面上方的流动形式、风速及湍流强度分布特征进行了模拟计算,结果表明:平屋顶最利于屋顶风力机的安装,其次为金字塔屋顶,最差为斜屋顶和三角形屋顶;对于金字塔屋顶、斜屋顶和三角形屋顶这些非平顶建筑物,不合适安装低于屋顶最高位置的屋顶风力机,且可优先考虑将屋顶风力机安装于屋檐;为了避开强湍流区域,以上四种屋顶形状顶面屋顶风力机的安装高度不得低于1.1H;在建筑物群内,当安装高度高于1.2H后,屋顶风力机安装于第一排建筑物顶面任何位置时都可避开屋顶的强湍流区域,而此排建筑物顶面风速达到来流风速的高度随着屋顶形状的不同而不同;当安装高度高于1.5H后,可忽略屋顶形状的不同,将屋顶风力机安装于群内所有建筑物顶面任何位置。

The purpose is to explore the flow pattern,wind velocity and turbulence intensity over the aligned arrays buildings with flat roof,gabled roof,pyramidal roof,and pitch roof,respectively.The suitable wind profile based on urban rough atmospheric boundary layer is applied in the inflow condition and Realizable k-ε turbulence model is utilized in the simulations.Results from this investigation shown that the flat roof is the best for installation of the wind turbine,then the pyramidal roof is the secondary,and the pitch and gabled roof are the worst.Meanwhile,the installation height must be higher than 1.1 times of these four rooftop.For the non-flap buildings,it is not suitable to install the wind turbine at the height lower than the top of the building,while the eaves of the rooftop are the best installation locations.Moreover,for the height is higher than 1.2 H,the wind turbine should be installed at the front row of the building group,where the wind turbine exposes to the wind flow without high turbulence intensity,and the capability of wind flow recovery varies with the different roof shape.For the height is higher than 1.5 H,the influence of the roof shape can be ignored,and the wind turbine can be installed at the arbitrary locations at the rooftop in the building group.