高原山体遮挡对湖泊和城区风场的影响

Influence of plateau mountain block on lake and urban wind field

为了探究高原山体遮挡对湖泊和城区上空风场变化的影响,选取昆明市西山和西山东侧的草海及部分城区为研究对象,以1∶1 800的缩尺比制作了实物模型,利用风洞实验模拟了有山体遮挡和无山体遮挡在主导风西南风作用下的风场变化,并结合数值模拟验证了有山体遮挡情况下的风洞实验。实验结果表明:山体遮挡对下风向的山脚区和湖泊区风速影响较大;山体高度为260和460 m时,距离山体4 500 m范围内山体对下风向山脚区和湖泊区中部及南部的风速削减较大;山体高度为110 m时,山体对下风向区域的影响主要体现在对山前风速的削减,并未对湖泊和城市区域产生较为明显的风速梯度变化。

In order to investigate the change of wind field affected by plateau mountain （Xi mountain）,the research object chose the area between lake （Dianchi） and urban （Kunming）.In this study,the physical model with the scale of 1 ∶ 1 800 was used in the wind tunnel.The wind field changes due to dominant wind were simulated with and without mountain-effect respectively.To verify the wind filed change by the mountain-effect,the numerical simulation was progressed.The results indicated that the wind speed change of the hillside area and the lake area were apparently affected by the mountain block.At the heights of mountain 260 and 460 meters,wind speed of the hillside and the lake area within the 4 500 meters away from the mountain were significantly influenced.In case of a relative altitude of 110 meters＇ mountain block,the influence of plateau mountain block on wind field was significant in front of the mountain compared with the effect on lake and urban area.