The Numerical Simulation Of Downburst Based On Arps Model

Today, the downburst regarded as one important weather reason for destruction of tall buildings (especially for damage of transmission tower), has aroused world wide attention and research in the field of wind engineering. However, China's design specification of high-rise wind sensitive structures has not considered strong wind load, the downburst wind as a class of strong thunderstorms wind, its study is of great significance.Throughout the downburst research in the field of wind engineering, both the physical simulation and CFD numerical simulation were not taken into account evolution and extinction mechanism of downbust, so the simulation of downburst always has the problem of distortion. However, the downbust research in the field of meteorology focused on theoretical research but not for simulation purposes, so the distortion problem also exists. In view of above, combine the field of wind engineering and meteorology, the numerical simulation of downburst for simulation purposes using meteorological instruments is particularly necessary.Firstly, from the meteorological point of view, the article introduced meteorological background knowledge, including the synoptic scale, atmospheric convection and mesoscale convective weather systems, so as to bring downbust basic understanding, including its definition, basic characteristics, influencing factors, formation and mesoscale background.Then, the article introduced the ARPS numerical weather models, including the main features of ARPS model, the control equation, the physical processes and model structure. And a brief description of the ARPS model installed in the Linux operating system.Finally, the Guangzhou Baiyun Airport "7.21" downburst and Wuhan, "6.22" crash downbust were simulated, to testify ARPS simulation capability and credibility of the output data, and verify the simulation results through the basic characteristics of meteorological field.Proved that the simulation capacity of ARPS model for lower resolution mesoscale weather system was better. The simulation results for the case "7.21" succeeded, but the case "6.22" failed. The reason for the failure of the case "6.22" is most likely that the downburst did not occur in the background with very significant mesoscale convective system, and the model smoothed out some of disturbance. Way to solve the problem is to change the initial field data, using the higher resolution data or adding radar, sounding data into the original data. In fact, the lack of high-resolution data of downburst is a major difficulty in this topic. These depend on the development of China's meteorology, Establishment of small scale weather station network and Large-scale field tests by radar are the key to solve this difficulty.