台风三维风场的实测、模拟及应用研究

Typhoon is one of the most destructive natural disasters that can cause severe casualties and economic losses every year. Knowledge on TC wind characteristics lays the basis for the prevention and reduction of TC-induced disasters. Thus, it is of great importance to better explore TC wind characteristics. However, most existing studies concern with TC wind within a much shallower TC depth, whereas investigations of TC wind and other TC structural features throughout the entire TC depth are notably limited. The lack of TC studies from a comprehensive and global perspective restricts the scope of validity of current understanding of TC wind to some extent. .This project focuses on a comprehensive investigation of TC wind field, which contains three successive tasks: (1) Observational study of TC thermodynamic and kinematic structures within the whole TC depth; (2) modeling of TC spatial pressure and wind fields below TC outflow layer; (3) determination of vertical profile of TC-dominated design wind speeds, and assessment of TC-induced wind effects on super-tall buildings. Task 1 will be carried out on the basis of over 20-years’ observational data from various types of measurement instruments. TC thermodynamic and kinematic structures over the entire TC depth will be investigated in a framework using both case study and composite analysis methods. Vertical profiles of horizontal wind speed, atmospheric pressure, temperature and relative humidity within the whole TC depth will be presented. In Task 2, a three-dimensional (3D) TC pressure field model will firstly be constructed by a combined use of the observed vertical profiles and an existing radial model. Secondly, the proposed TC pressure field model will be applied in conjunction with an existing TC wind field model to establish a refined 3D TC wind field model. The established model will take into account the outward tilting feature of the radius of maximum wind (RMW) and the vertical variation of horizontal eddy viscosity. Thirdly, a novel vertical profile model of TC horizontal wind speed will be proposed for practical purposes. This model will be able to replicate the low-level-jet (LLJ) feature of TC wind and its dependence on radial position. Task 3 deals with two important issues in wind engineering practices. First, TC-dominated design wind speeds in Hong Kong at several return periods will be determined using the Monte Carlo simulation techniques and the newly-established 3D wind field model. Results will be presented in the form of vertical profile rather than a speed value at a specific height from most preceding literature. Second, wind tunnel tests with more realistic approaching TC wind fields (e.g. LLJ and veering wind) will be performed on both rigid and aero-elastic models of two iconic super-tall buildings. Flow fields around the building models, wind forces on building facades and model base, as well as wind-induced displacement and acceleration response at the top of the buildings will be examined and compared with field measurement data from the installed structural health monitoring system. .The outcomes from this study are believed to enhance current understanding of TC structure and wind field, and to provide valuable implications for wind engineering practices.

台风是一种破坏力极强的复杂气旋系统，每年都会给我国沿海地带带来巨大的经济损失和人员伤亡。合理确定台风风场特征是诸多抗风实践活动的基础。然而风工程界当前大部分相关研究均局限于近地表面范围，涵盖更厚台风高度范围的研究非常有限。这限制了人们从全局范围解析台风风场特征，进而影响了部分既有研究成果的适用性。本项目将在更厚范围内对台风的风场特征进行实测、模拟及应用化研究。实测研究将基于探空气球、机载GPS-dropsonde和雷达风廓线仪等录得的气象数据，对台风整体厚度范围内的热力学及风场特征进行个例和复合分析。基于实测结果将建立台风三维气压场及三维风场模型；将采用台风全路径蒙特卡罗数值模拟技术并结合所提三维风场模型对我国东南沿海台风极值风气候特征进行评估，结果以风剖线形式给出。基于实测及模拟结果将对超高层建筑风效应进行风洞实验研究，对比考察采用传统风场及更为真实的来流风场建筑风效应的差别。

台风是一种破坏力极强的复杂气旋系统，每年都会给我国沿海地带带来巨大的经济损失和人员伤亡。合理确定台风风场特征是诸多抗风实践活动的基础。然而风工程界当前大部分相关研究均局限于近地表面范围，涵盖更厚台风高度范围的研究非常有限。这限制了人们从全局范围解析台风风场特征，进而影响了部分既有研究成果的适用性。本项目在更厚范围内对台风的风场特征进行实测、模拟及应用化研究。（1）基于长期多源化气象观测资料，对台风典型全局化结构特征进行了个例研究和汇总分析，提出了沿高度解析的台风气压场模型及地表轴非对称模型，以此为基础建立了沿高度解析的台风风场模型及台风全局化风剖线模型；（2）开展台风风场实测研究，详尽分析了台风不同阶段、不同地貌来流情况下边界层风场特征，提出了激光风廓线仪脉动数据修正方法以及离岸岛屿近地面风场实测数据标准化方法；（3）基于华南地区气象监测网长年实测数据分析台风关键参数特别是最大风速半径和Holland-B数值，得到了沿海四城市台风关键参数统计模型，并采用抽样模拟技术对台风极值风气候特征进行了评估；（4）发展了基于卫星云图的台风指纹、中心位置和强度等关键参数的人工智能识别方法及短时预测技术，发现了气候变化立体式、多元化表现特征并评估了其对未来台风活动的影响，有效推动了结构抗台风领域风场信息问题的解决；（5）采用风洞试验及现场实测结合的技术，考虑台风偏转风、台风核心区域空气密度沿高度变化、台风与良态风脉动特征的差异，评估高层建筑台风风效应。.依托该项目，以第一或通讯作者身份发表期刊论文24篇，其中SCI论文22篇、EI论文2篇，会议论文4篇(含大会特邀报告1篇)；授权中日发明专利4项、软件著作权3项。部分研究成果被气象部门及建筑设计单位采纳，产生显著社会经济效益。