Numerical Study Of Wind Pressure Distribution And Mutual Interference Characteristics On High-rise Buildings Under Downburst

Downburst is a kind of destructive natural phenomenon,its strong sinking airflow produced in the thunderstorm weather.lt slams into the ground from a certain height of the atmosphere in a very short time,and accelerates the extension from the impacting area,influencing radius from 2 km to 40 km,which is different from the characteristics of normal wind in atmospheric boundary layer.It often causes a large number of serious damage or collapse of engineering structures that brings great loss.Therefore,the research of downburst for the international wind engineering is more and more taken seriously.And it is quite necessary to study the characteristics of wind fields and its effect on the buildings under downburst.In recent years,with the rapid development of computational theory and hardware technology,numerical simulation has been widely used in the field of wind engineering.Based on RANS equations and RNG κ-ε model,the wind pressure distribution on high-rise buildings which are located in different positions away from the center of downburst and the influence of interference characteristics on wind pressure distribution of buildings for different layouts are simulated by constructing three-dimensional CFD field under downburst,focusing on obtaining interference characteristics and change law of pressure distribution.First of all,the downburst field of an isolated high-rise building is simulated.The characteristics of wind pressure distribution on the surfaces of the high-rise building which is located in different positions away from the center of downburst is obtained.Then numerical simulation is performed to further determine the downburst field of two buildings with the same geometrical shape for different layout which are located in different positions away from the center of downburst.The influence of the interfering building on interfered building on wind distribution is analyzed and the law of interference characteristics is obtained.The interference characteristics of the interfered building is focused to study when two buildings are series and parallel.Finally,the characteristics of wind pressure distribution on high-rise group buildings consisting of four buildings which are located in different positions away from the center of downburst are simulated,and the wind pressure distribution characteristics are analyzed and compared with the results of pressure distribution on building group under normal wind in atmospheric boundary layer and some laws are obtained.The result shows the wind pressure distribution of group buildings has its own main features,that is different from the monomer due to interference.The results of this paper can provide reference and guidance for the research of the effect of downburst and wind resistant design of super high-rise buildings and complex group buildings.