Refinement Of Typhoon Wind Field Simulation

Typhoon has brought plenty of rain to many areas, and has become the rainfall system closely related to human life and production. However, the typhoon will bring serious damage, it has the characteristics of sudden strong, destructive, is one of the world’s most serious natural disasters.The main research of typhoon is: Meteorology give full consideration to all kinds of elements of the atmospheric physics process, analysis of typhoon formation,development and demise process. But it is mainly for large-scale typhoon simulation.Civil engineering does not consider the temperature, humidity, water vapor and other physical processes, simplification of the governing equations is obtained, although the mechanism of typhoon research has obvious flaws, but provide useful information on the analysis for the safety of the structure design. Professional hazard assessment and insurance industry is focused on the probability analysis of occurrence of typhoons,landing, take into account all uncertainties and statistical regularities.In this paper, atmospheric meteorology equations are used for small-scale typhoon wind field simulation, compared with the traditional independent study has the advantage of not only ensure the relatively accurate simulation of typhoons, but also can extend the simulation information to the small-scale region, which is a good research ideas for civil engineering. The subject use the atmospheric fluid control equations for typhoon weather system numerical simulation, obtain the fine 3D typhoon field spatio-temporal information and analysis of typhoon wind field structure and characteristics of the wind field, further consideration that may affect the results of the simulation: rotation of turbulence factors, spatial and temporal precision and subgrid model, modify the source code or add new subgrid model for analysis. The objective of this paper is to get fine and accurate typhoon wind field by numerical simulation, which is convenient for large bridges, wind power farm siting, urban wind environment research development, and find new phenomenons in the field of meteorology and civil engineering concern connection area, then give reasonable theory to interpretation the new phenomenon. In this topic, the simulation is used by the unified mesoscale numerical model WRF, which is developed by the US Centers for Environmental Prediction and the National Center for Atmospheric Research and other research institutions. Specific contents are as follows:First, use WRF to simulate the 1416 typhoon Feng Huang, divided two conditions:WRF and WRF-LES simulation, comparative analysis of typhoon wind field characteristics, optimized better simulation results working conditions as the main basis for subsequent analysis. During the analysis, it was found that the mean velocity profile and the terrain of typhoon center has a close correlation, there is a transition sectionbetween the stationary phase and the high frequency range of the fluctuating wind velocity spectrum, which is different from the boundary layer spectrum Kolmogorov-5/3 law, turbulence intensity, turbulence integral scale is also quite different with normal wind.Then, the possible reasons of the "strange" of the fluctuating wind speed spectrum are analyzed: rotating turbulence, temporal and spatial accuracy and WRF model subgrid model accuracy. at the same time simulation of a normal weather systems,comparative analysis of spectral characteristics of fluctuating wind velocity, draw all possible factors that affect the specific situation of the typhoon system.Finally, combine the phenomenon of the normal weather system, find out the reasonable theory explanation of the "strange" of the fluctuating wind speed spectrum--the concept of enstrophy and geostrophic balance.From the above analysis, the new phenomenon can be explained in theory, and can optimize the more accurate scheme of the typhoon wind field both in the large scale and small scale, and complete the original intention of the project.