Research On Factors Affecting The CFD Numerical Simulation And Application In Downburst

The methods of researching wind engineering contains field measurement, theoretical analysis,wind tunnel test and numerical simulation. With the development of computational technology, CFD numerical simulation shows promising prospect by its unique merits, and gained more and more attention. But, there are many difficulties in the process of computing the complex flow field around the lower atmosphere boun-dary layer. This thesis focuses on the numerical simulation technology for wind loads, introduces the basal theoretic, models, factors and methods; constitutes the standard about the numerical domain dimension, turbulence models and gridding size by simu-lating corresponding models.Other work in this thesis is researching on the downburst comes forth during thun-derstorm. The wind field characteristics of downburst are quite different from boundary layer winds. Two parts of words have done by CFD numerical simulation. (1) Founding and simulating both 2D model and 3D model, then find that the result of scale and Velo-city are fitted to the typical wind profile.(2)Placed both Large-span structure models and high structure models at different radial locations (r=0D,r=0.5D,r=1D,r=1.5D,r=2D and r=3D).Pick up the pressure coefficient distribution on every faces, and the nodes resultant force of different radial locations models'roof. These result can offer inform-ation for wind engineering.