基于CFD数值模拟的古建筑群风场特性研究——以北京故宫建筑群为例  

Study on wind field characteristics of ancient building group based on CFD numerical simulation:Taking the Forbidden City building group as an example

作　　者：韩宜丹 淳庆[1] HAN Yidan;CHUN Qing(School of Architecture,Southeast University,Nanjing 210018,China)

机构地区：[1]东南大学建筑学院,江苏南京210018

出　　处：《西安建筑科技大学学报（自然科学版）》2024年第5期650-659,共10页Journal of Xi'an University of Architecture & Technology(Natural Science Edition)

基　　金：国家自然科学基金(51778122);江苏省重点研发计划项目(BE2022833)。

摘　　要：为研究我国古建筑群风场特性评估方法,基于计算流体动力学方法(Computational Fluids Dynamics,CFD),以北京故宫建筑群为例,通过对不同风向角工况下的故宫建筑群进行CFD数值模拟,获得全域流场信息,包括故宫中轴线主要建筑的表面风压分布情况、以及故宫建筑群环境风速分布情况.研究揭示了故宫建筑群内不同风向角下主要建筑表面的风压分布规律、中轴线建筑的不利风向角,并基于风环境评估理论对故宫建筑群内的行人风环境舒适性和安全性进行评估.研究结果表明:风压分布大致呈东西和南北对称分布形态;迎风面受较大正风压,侧风和背风面受较大负风压,负风压主要集中在靠近屋脊和墙面转角等气流分离区;主要建筑表面的正风压系数最值达1.0,负风压系数最值达2.2;六座大殿所受竖直方向的升力系数极值接近8,是水平方向的2倍;在水平和竖直方向上风压合力在斜风向下较大,其中在120°时的三向风压合力均达到极值;环境最大风速比在3~6之间,斜风向的最大风速比较大;垂直风向下,风速放大效应较弱,其中正南和正北风放大效应最弱,北京地区的主导风向是故宫建筑群的最优风向.研究成果可以为故宫建筑群的结构抗风保护以及行人防风措施提供科学依据和指导.The study reveals the wind pressure characteristics of the main building surface and the unfavorable wind direction for the central axis buildings,and evaluates the comfort and safety of pedestrian wind environment based on the wind environment assessment theory.The results show that the distribution of wind pressure roughly follows a symmetrical pattern of east-west and north-south distribution.The windward surface is subject to positive wind pressure,while the crosswind and leeward surfaces are subject to negative wind pressure.The negative wind pressure is mainly concentrated in the airflow separation area near the roof ridge and the corner of the wall.The maximum positive and negative wind pressure coefficients of main building surface are 1.0 and 2.2,respectively.The extreme lift coefficient in the vertical direction is close to 8,which is twice as high as that in the horizontal direction.The force coefficients are larger under the oblique wind direction,and reach the extreme values at 120°.The maximum wind speed ratio of the environment is between 3 and 6,and the maximum wind speed of the oblique wind direction is larger.The wind speed amplification effects are weak under vertical wind directions,among which the north and south wind amplification effect are the weakest.The dominant wind direction in Beijing is the favorable wind direction for the Forbidden City.The results can provide scientific basis and guidance for the structural protection of buildings and pedestrian protection measures of the Forbidden City building group in view of wind resistance.

关 键 词：CFD数值模拟 故宫建筑群 平均风压系数 风环境模拟 

分 类 号：TU398[建筑科学—结构工程]