高层建筑二维流场的数值模拟

针对建筑物风场的高雷诺数特点,采用离散涡法,分析了高层建筑物的非定常分离流问题.通过引入奇异点技术摆脱了保角变换的处理过程,使离散涡法能适应于复杂形状的钝体结构.数值模拟了流场的变化特征,分析了各种攻角下,具有方形截面的高层建筑的升力系数、抗力系数和Strouhal数.计算分析表明,离散涡法具有计算速度快及精度高的特点,可以刻画出流场的流动特征,透视到流动机理,在结构风工程领域具有较好的应用价值.

Numerical Simulation of Two-dimensional Flow Past a Tall Building

In accordance with the characteristics of high Reynolds number for building wind field, the discrete vortex model is developed to analyze the unsteady separated flow of a tall building with rectangular cross section. The flow is assumed to be a potential flow except in the region of the free shear layers which are shed downstream from the separation points, the region and the building are represented by discrete vortices. The present discrete vortex model combined with singularity method can be easily applied to a building with complicated shape. The characteristics of wind field are numerically simulated, the lift and drag coefficients and Strouhal numbers are analyzed for several angles of attack. The results show that the discrete vortex model can provide a powerful tool for depicting the field character and flow mechanism in building wind engineering.