Numerical Simulation Of Wind Loads And Open-loop Active Control On High-rise Building

With the development of economy and the explosion of population, high-rise buildings have been developed greatly. Wind load is one of the dominant loads on high-rise buildings. As a result of extensive utility of high-strength and light-weight materials in construction, high-rise buildings inclined to be more flexible with a lower damping ratio, the effect of wind load increased prominently. Most present researches focus on the statistic characteristics, spacial correlations and power spectral of wind load, in order to evaluate the equivalent static wind load. And the study of wind load from the perspective of bluff body aerodynamic forces is less. High-rise buildings can be simplified as a finite length bluff body with a free-end mounted on a ground plane. Therefore, the study of near wake structures and aerodynamic forces is the key of high-rise buildings research and has great significance to wind load resistance research on the high-rise buildings.Based on computational fluid dynamics software FLUENT6.3, the flow of the finite length square cylinder with aspect ratio5at Re=3900uniform incoming flow was investigated, using large eddy simulation in the paper. Firstly, the more detail of research are discussed such as flow domain, grid, boundary condition and time step. Then, the time-averaged and transient characteristics of aerodynamic force and wake were investigated. The instantaneous result suggests there are two typical flow statuses presence in the near wake alternately:first, the spanwise vortices are staggered arranged similar to that in2D cylinder wake; second, the spanwise vortices are quasi-symmetrically arranged. This paper aimed to analyze the influence mechanism of aerodynamic force and wake through lift and drag force, flow structure, velocity in two flow mode. Finally, active control with slot jet was imposed on the finite length square cylinder based on the understanding of aerodynamic force and wake. The interaction between the jet and wake will be studied.