摘要
采用R ea lizab le k-ε双方程模型和P ISO算法,在正弦型周期变化风谱所形成的大气边界层对数风速廓线下,对绕三维建筑物的流动进行了数值模拟.采用分区网格划分方法,应用自适应网格技术,固体壁面采用标准壁面函数法处理.计算结果显示,整个流场都随正弦风谱呈周期性波动,各点速度的变化周期相同,只是幅度有所改变.周期的变化对整个流场速度的大小影响较小,但振幅的改变可使速度值发生很大变化.在建筑物周围,受阻挡的气流被挤压而绕流,横剖面后部形成两个旋转方向相反的大尺度涡;纵剖面后部分离后产生与H相同高尺的分离涡,回流区长度在0.15 m左右,且不随周期和振幅而改变,整个流动具有对称性.
Realizable k-ε model of turbulence and PISO method were applied to numerical simulation of the stream field around 3-D building under the unsteady airflow. The atmospheric boundary layer and natural wind was considered and the sinusoidal gust sequence was constructed for inlet boundary condition of computational region. The boundary conditions near the solid walls were analyzed using the method of standard wall function. The results show that the fluctuating periods of the velocity value at different point agree with the sinusoidal gust sequence and the amplitude is simply at variance in all flow area. The effect is small on the velocity value when the periodicity is changed. But great effect exist when the amplitude is changed. Two big vortex which have counterturn are formed in y= 0.02 m section back of the building, and the recirculating eddy which have the same scale as H in z=1/2B section back of the building vary with neither the periods nor the amplitude.
出处
《西安建筑科技大学学报（自然科学版）》
CSCD
北大核心
2005年第3期311-315,共5页
Journal of Xi'an University of Architecture & Technology(Natural Science Edition)
基金
国家"十五科技攻关"重大项目(2004BA901A21)
