支撑结构对定日镜绕流风场特性的影响分析

Influence of support structure for heliostat wind field distribution characteristics

为了研究塔式太阳能定日镜绕流风场的各项特性,文章采用计算流体动力学方法对定日镜绕流风场的分布情况进行数值模拟,并通过模拟结果分析了定日镜绕流风场的分布特征及其产生的原因。分析结果表明:来流冲击定日镜后,滞点位置以下的部分流体经定日镜和地面之间的窄隙流出,形成狭管效应并在定日镜背后近地面处产生流动加速区;绕流至定日镜背面的流体在定日镜面板与支撑立柱之间产生二次钝体绕流,在定日镜和立柱之间形成分布情况比较复杂的风场;来流在定日镜背后形成的上、下两个方向相反的涡结构,这是沿来流方向从定日镜背面至远端近地面的大范围高风速区域产生的主要原因。

In order to study the influence of support structure for heliostat wind field distribution characteristics,the wind field around a heliostat was simulated by Computational Dynamics Fluid(CFD).The CFD results were validated by the wind-tunnel experimental results.The wind filed characteristics around the heliostat and causes were discussed.The results indicate that,after impacting the heliostat,the flow pass through the narrow gap between the ground and the heliostat,which brings a velocity acceleration zone behind the heliostat on account of the tube effect.A secondary bluff body flow is generated between the heliostat and the support column,which causes the complex wind distribution on the heliostat.The two upper and lower vortexes behind the heliostat in opposite direction are the main cause of the large range of high wind speed values region extending from the half-height position of the heliostat to the far-end near the ground.