摘要:近地表地形的风场受坡度坡向、地表形态和空间格局等地形要素的控制，从而影响人的"风感"体验，是人居环境的选址与布局需要考虑的重要因素。通过建立地形3D模型、划分网格、设定模拟工况，运用Fluent 14.0软件对不同山体地形坡度、形态和格局的风场进行CFD （Computational Fluid Dynamics）模拟。结果发现：（1）坡度在0.3以下对地形风场影响较小；当坡度大于0.5时，随坡度增大背风坡风影区逐渐增大，挡风效果更加明显；坡度大于0.7以后，随着风影区加大，回流涡旋更加明显。（2）风场受到周边地形形体的影响，尤其是迎风面和背风面截面变化率。迎风面截面变化率越大，风速变化越快；背风面截面变化越大，背风面的出现风影区和回流涡旋的几率越大。迎风面出现凹形迎风口会形成气体滞留区，而背风面凹形口后部会增加风影区和回流涡旋出现的几率。（3）不同地形格局对单个地形的风场具有强化和减弱效果。"三面环山"的相对封闭的地形格局有利于形成稳定的风场，并提高风感舒适度。在人居环境的风感营造和优化中，需要避开风感敏感区域，即风速激增区、回流涡旋区、无固定风向的强烈湍流区、气流不流通的静风区和气流死循环涡旋区等风感敏感区，并利用植被或者人工构筑物来消除敏感区或削弱这一影响。并根据不同的气候类型和城市特点进行选址、地形改造或者进行内部地形格局调整和优化，以提高风感舒适度。选择开放型地形格局和低坡度、平行风向的流线型地形能够加强通风，而塑造封闭性地形格局和垂直风向的陡坡地形能够减小风速。



Abstract:The wind field of near surface topography is controlled by the terrain factors such as slope and aspect, surface morphology and spatial pattern, thus affecting people's "wind feeling", which is important in the site selection and layout of human settlements. By establishing 3D terrain model, dividing grid and setting simulation conditions, this paper uses Fluent 14.0 to simulate the wind field of different slope, shape and pattern of mountain terrain. The results show that:(1) the slope below 0.3 has little influence on the terrain wind field; when the slope is greater than 0.5, the wind shadow area of leeward slope gradually increase with the increase of slope, and the wind resistance effect is more obvious; when the slope is larger than 0.7, the return vortex becomes more obvious with the increase of wind shadow area. (2) The wind field is affected by the surrounding terrain, especially the change rate of the windward and leeward sections. The larger the change rate of windward section is, the faster the wind speed changes; the greater the change of leeward cross-section is, the greater the probability of occurrence of wind shadow area and circumfluence vortex on leeward side. The presence of a concave inlet on the windward side will strengthen the gas retention zone, while the rear of the concave opening on the leeward side will increase the probability of the occurrence of wind shadow area and reflux vortex. (3) Different terrain patterns can strengthen and weaken the wind field of a single terrain. Through the simulation of the traditional terrain pattern of "surrounded by mountains on three sides", it is found that the relatively closed pattern is conducive to the formation of stable wind field and the improvement of wind comfort. When constructing and improving the windsense of human settlements, it is necessary to avoid the wind sensitive areas in different terrain, such as high wind speed ratio area, reflux vortex area, turbulent area without fixed wind direction,no wind area and vortex area of air circulation. Vegetation or artificial structures should be used to remove or weaken the wind sensitive area. According to different climate types and urban characteristics, the windsense can be improved through site selection, terrain transformation or internal terrain pattern adjustment. The open terrain pattern,the streamlined terrain parallel to wind with low slope can enhance ventilation, while the closed terrain pattern, the steep terrain vertical to wind can reduce wind speed.





PDF全文下载地址:

https://www.ecologica.cn/stxb/article/pdf/stxb202007241939