【作者】 陈平；

【导师】 陈水福；

【作者基本信息】 浙江大学 ， 结构工程， 2007， 硕士

【摘要】 气流经过山地丘陵地区时，该地区复杂的地形、地貌将显著改变近地流动风的风速、风压和湍流结构，使得这些地区的风流场呈现与平坦地区较明显的差异，造成风速和风压的分布很不规则。研究山地丘陵地区的风流场分布特点以及流场随不同山丘高度、坡度和不同来流风向角的变化规律，对山地丘陵城镇合理选址及抗风设计均有重要意义。本文采用基于计算流体动力学的数值模拟方法，首先在二维情况下，对典型地形情况的区域风流场(风速、风压及湍流结构等)进行较系统的计算分析，探讨单坡地形的坡角、坡峰、坡谷的相对尺寸对坡顶风速、湍流结构、风速剖面等的影响规律以及双坡地形中不同高度山丘之间的相互影响效应。然后在三维情况下，探讨不同坡度的孤立山丘周围风速场和风压场的分布，在此基础上对山谷狭道效应的形成机理和过程做了直观的分析，并研究了不同风向角情况下峡谷内外风场的变化情况。文章最后结合实际地形情况，讨论了由三个不同高度、不同坡度的孤立山丘组成的复杂地形模型，在不同风向角情况的风场流动特性。通过对比分析可得，对于简单的、坡度较小的地形，山丘周围的风速变化可以较准确的由一些经验公式，例如MSFD理论模型计算得出；而对于坡度较大的以及较复杂的地形，经验公式无法较准确地对风速做出估算，只能借助于数值模拟来分析。本文在总结不同地形的流动风场分布特点的基础上，提出了对山地建筑物选址的一些建议。更多还原

【Abstract】 While air flows over hilly lands, the complex terrain features and physiognomy will observably change turbulence characteristic, wind speed and wind pressure of boundary-layer flow, which results in hilly land’s flow environment is much different from plat land’s and results in the distributing of wind speed and wind pressure is much anomalistic. So, to research about the characteristic of flow field distributing in hilly area and the rules of flow change results from variety hill height, slope and variety airflow angle is significant for both choosing an appropriate city address in hilly lands and wind resistance design.By adopting numerical model method which bases on Computational Fluid Dynamics, in the first place, for 2D model, it systemically computed and analyzed the airflow field (such as wind speed, wind pressure and turbulence characteristic) of typical terrain, discussed the influence laws of single hill’s slope angle, relative size of crest and valley on wind speed of hilltop, turbulence frame, wind profile and so on. The interaction between variety height hills in double hill terrain is also discussed. And then, for 3D model, the wind speed and wind pressure distributing of single hill with diverse slope is researched. Based on it, the principle and process of narrow channels effect forming is showed visually and the change of airflow field in the valley and out of the valley under different wind angle is studied. In the end, considering real terrain, a complex hilly model was formed by three single hills of different heights, different slope, whose airflow characteristic was researched under different wind angle.By comparing and analyzing, it is concluded that for simple and slow slope terrain, the change of wind speed around hill can be truly calculated by some experimental formula such as MSFD calculations. While for cliffy slope and complex terrain experimental formula can’t calculate the wind speed truly, it is well to analyze the question by numerical simulation. Based on the distributing characteristic summarization of airflow field in various terrains, some advice about building address choosing was put forward.更多还原