下击暴流强风冲击作用下定日镜风压时变特征  

Variation characteristics of wind pressure on heliostat under impact of downburst strong wind

作　　者：吉柏锋[1] 赵进新 姜峰 熊倩 瞿伟廉[1] Ji Baifeng;Zhao Jinxin;Jiang Feng;Xiong Qian;Qu Weilian(Hubei Key Laboratory of Roadway Bridge and Structure Engineering,Wuhan University of Technology,Wuhan 430070,China;School of Civil Engineering,Sun Yat-Sen University,Guangzhou 510275,China;School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学道路桥梁与结构工程湖北省重点实验室,武汉430070 [2]中山大学土木工程学院,广州510275 [3]武汉理工大学土木工程与建筑学院,武汉430070

出　　处：《东南大学学报（自然科学版）》2021年第5期790-796,共7页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51308430);湖北省自然科学基金资助项目(2020CFB524);武汉理工大学道路桥梁与结构工程湖北省重点实验室开放课题基金资助项目(DQJJ201907).

摘　　要：为研究下击暴流强风冲击作用下定日镜表面风压变化特征,基于计算流体动力学的方法对下击暴流瞬态风场中不同工作姿态的定日镜表面风压进行数值模拟.结果表明,受到下击暴流形成扩散过程引起的近地面风场变化影响,在下击暴流的冲击作用下定日镜迎风面和背风面风压都表现为先增大后减小的时变特征,背风面比迎风面提前达到压力峰值,且迎风面和背风面瞬时峰值压力均明显大于稳态风场中的相应峰值压力.同一时刻下,定日镜迎风面正压峰值中心随着俯仰角的增大逐渐向上移至镜面中心,风压系数峰值可达1.4,背风面负压峰值中心随俯仰角增大逐渐向两侧水平偏移,风压系数峰值由1.8减小到1.0.在小俯仰角工作姿态下定日镜背风面会遭受更大的负压作用,说明现行的定日镜抗风设计中采用的小俯仰角避险姿态并不完全适用于下击暴流强风作用的状况.To study the variation characteristics of the wind pressure on the surface of the heliostat under the impact of downburst strong wind,the wind pressure on the surface of the heliostat with different working postures in the transient wind field of the downburst was numerically simulated based on the method of computational fluid dynamics.The results show that under the influence of the change of the near-surface wind field caused by the formation and diffusion of downburst,the wind pressure on the windward side and the leeward side of the heliostat shows a time-varying characteristic that first increases and then decreases under the impact of downburst.The leeward side reaches the pressure peak earlier than the windward side,and the instantaneous peak pressure on the windward and leeward sides is significantly greater than the corresponding peak pressure in the steady wind field.At the same moment,the peak center of the positive pressure on the windward surface of the heliostat gradually moves upward to the center of the mirror surface as the pitch angle increases,and the peak value of the wind pressure coefficient is 1.4.The peak center of the negative pressure on the leeward surface gradually shifts horizontally to both sides as the pitch angle increases,and the peak value of wind pressure coefficient decreased from 1.8 to 1.0.The leeward side of the heliostat suffers more negative pressure under the working posture of the small pitch angle,showing that the small pitch angle avoidance posture adopted in the current anti-wind design of heliostats is not completely suitable for considering the effect of downburst.

关 键 词：下击暴流 瞬态风场 定日镜 风压 数值模拟 

分 类 号：TU312.1[建筑科学—结构工程]