精细化台风风场模拟

发布时间：2018-05-04 08:11

本文选题：台风 + 中尺度数值模式WRF　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：一方面台风与人们的生产、生活密切相关,给沿海及内陆地区带来了充足的雨水;另一方面,台风是最严重的自然灾害之一,具有突发性强、破坏力大等特点。关于台风的研究主要有:气象学从台风的形成、发展以及消亡的整个大气物理过程着手,充分考虑台风天气系统的各类要素,但主要是对台风进行大尺度的模拟;土木结构领域未考虑温度、湿度、水汽等物理过程,得到简化的控制方程,虽然对研究台风机理有着明显的缺陷,但为结构的安全设计提供较好的分析资料;灾害评估专业以及保险行业则是着重台风的发生、登陆等概率分析,充分考虑各种不确定因素以及统计规律。本文采用气象学大气控制方程组进行小尺度的台风风场模拟,较之传统相互独立的研究,其优势在于既保证了台风模拟的相对准确,又能将模拟信息延伸到小尺度区域,这对土木工程来说是一种很好的研究思路。首先进行台风天气系统的数值模拟,得到精细三维台风场时-空信息,分析台风风场结构、风场特性;进一步考虑可能影响模拟结果的旋转湍流因素、时空精度和亚格子模型,修改源程序或加入新的亚格子模型进行分析。本文目标是通过数值模拟得到精细、准确的台风风场,便于大型桥梁、风力电厂选址,城市风环境等研究开展;并发现气象学与土木学科关注连接领域的新现象,对得出的新现象给出合理的理论解释。本文利用的是由美国环境预测中心和美国国家大气研究中心等科研机构开发的统一的中尺度数值模式WRF。具体研究内容如下:首先,利用WRF模拟2014年16号台风凤凰,分为WRF模拟和WRF-LES模拟两种工况,对比分析台风的风场特性,优选出模拟结果较好的工况作为后续分析的主要依据。在分析过程中,发现平均风速剖面与台风中心所处地形有着密切的相关性;脉动风速谱在平稳段与高频段之间存在一过渡段,这与科尔莫戈罗夫的-5/3次律的边界层谱有一定出入;湍流强度、湍流积分尺度同样与常态风相差较大;然后,重点分析引起脉动风速谱“异样”的可能因素:旋转湍流、时空精度以及WRF模式亚格子模型的准确性,得出各可能因素对于台风系统的具体影响情况;与此同时模拟一正常天气系统,对比分析脉动风速谱特点;最后,结合正常天气系统模拟出现的类似现象,找出脉动风速谱“异样”的合理理论解释--涡度拟能、地转平衡概念。通过上述分析,从理论上解释新现象,可以优选出在台风大、小尺度上都较为准确的风场信息方案,完成了课题的初衷。
[Abstract]:On the one hand, typhoon is closely related to people's production and life, which brings sufficient Rain Water to coastal and inland areas; on the other hand, typhoon is one of the most serious natural disasters, with the characteristics of sudden and destructive. The research on typhoon mainly includes: meteorology starts from the whole atmospheric physical process of typhoon formation, development and extinction, fully considers all kinds of elements of typhoon weather system, but mainly simulates typhoon on a large scale; In the field of civil structures, the simplified governing equations are obtained without considering physical processes such as temperature, humidity and water vapor. Although there are obvious defects in the study of typhoon mechanism, good analysis data are provided for the safety design of structures. Disaster assessment and insurance industry focus on the occurrence of typhoons, landing and other probability analysis, fully taking into account all kinds of uncertain factors and statistical laws. In this paper, the meteorological atmospheric control equations are used to simulate the wind field of a small scale typhoon. Compared with the traditional independent study, the advantage of the simulation is that it can not only guarantee the relative accuracy of the typhoon simulation, but also extend the simulation information to the small scale area. This is a good research idea for civil engineering. Firstly, the numerical simulation of typhoon weather system is carried out, and the fine three-dimensional time-space information of typhoon field is obtained. The structure and characteristics of typhoon wind field are analyzed, and the factors of rotational turbulence, space-time accuracy and sub-lattice model, which may affect the results of simulation, are further considered. Modify the source program or add a new sublattice model for analysis. The aim of this paper is to obtain fine and accurate typhoon wind field by numerical simulation, so as to facilitate the study of large-scale bridges, wind power plant location, urban wind environment, and to find new phenomena in the field of meteorology and civil engineering. A reasonable theoretical explanation of the new phenomenon is given. In this paper, a unified mesoscale numerical model, WRFF, developed by the Environmental Prediction Center of the United States and the National Center for Atmospheric Research in the United States, is used. The specific research contents are as follows: firstly, WRF is used to simulate 16 typhoon Phoenix in 2014, which is divided into two working conditions: WRF simulation and WRF-LES simulation. The wind field characteristics of typhoon are compared and analyzed, and the best simulation results are selected as the main basis for subsequent analysis. In the process of analysis, it is found that the mean wind speed profile is closely related to the topography of the typhoon center, and that there is a transition section between the stationary and high frequency regions of the fluctuating wind speed spectrum. This is different from Kormogorov's -5 / 3 law of boundary layer spectrum, turbulence intensity and turbulence integral scale are also different from normal wind, and then, the possible factors that cause pulsating wind velocity spectrum to be "unusual" are analyzed emphatically: rotational turbulence. The temporal and spatial accuracy and the accuracy of the sub-lattice model of WRF model are obtained. The influence of various possible factors on the typhoon system is obtained. At the same time, a normal weather system is simulated, and the characteristics of fluctuating wind speed spectrum are compared and analyzed. Combined with the similar phenomena in the simulation of normal weather systems, a reasonable theoretical explanation of "unusual" of fluctuating wind speed spectrum is found-the vorticity pseudo-energy and the geostrophic equilibrium concept. Through the above analysis, the new phenomenon can be explained theoretically, and the wind field information scheme, which is more accurate on the large and small scale of typhoon, can be selected, and the original intention of the project is fulfilled.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU312.1

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