西藏高原风场实测及非平稳风特性研究  

Wind field measurements in the Tibetan Plateau and the study of nonstationary wind characteristics

作　　者：楼文娟[1] 周为政 刘炯 梁明 蔡康 黄铭枫[1] Lou Wenjuan;Zhou Weizheng;Liu Jiong;Liang Ming;Cai Kang;Huang Mingfeng(Institute of Structural Engineering,Zhejiang University,Hangzhou 310058,China;Southwest Electric Power Design Institute Co.,Ltd.,China Power Engineering Consulting Group,Chengdu 610000,China)

机构地区：[1]浙江大学结构工程研究所,杭州310058 [2]中国电力工程顾问集团西南电力设计院有限公司,成都610000

出　　处：《东南大学学报（自然科学版）》2023年第4期575-584,共10页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51838012);中国能源建设集团规划设计有限公司科技资助项目(GSKJ2-D06-2020).

摘　　要：为研究高原风特性,于海拔4465 m的西藏南部浪卡子县离地10 m高度处进行了1年4季昼夜的风速风向实时连续采样实测,筛选出1256个有效大风样本.采用平稳模型、EMD非平稳模型及最优时变均值非平稳模型处理实测非平稳风速样本,分析了3种风速模型的平均风速、湍流强度、阵风因子、湍流积分尺度和脉动风谱等风场特性参数,并与低海拔地区多种类别风场实测结果进行对比.结果表明:西藏高原冬半年脉动风湍流强度大于夏半年;在相似地貌下,高原脉动风湍流强度要高于低海拔地区,而与一些特殊地貌及特殊风场如峡湾风、台风等的湍流强度接近;湍流积分尺度计算结果受风速平稳程度影响很大,平稳模型高估了湍流积分尺度;西藏高原脉动风拟合风谱与各标准谱均有一定差别,且具有较大的高频能量.因此,高原建筑结构抗风设计应注意高原脉动风参数与低海拔地区的区别,并充分考虑高原风的非平稳性,合理选择非平稳模型.To investigate wind characteristics in the Tibetan plateau,an ultrasonic anemometer was installed at a height of 10 m above ground in Langkazi County,Tibet,at an altitude of 4465 m.The wind velocity at the site was sampled continuously during all four seasons in a year,and 1256 valid samples of strong wind were obtained.The wind field characteristics such as mean wind speed,turbulence intensity,gust factor,integral length scale and wind speed spectrum are analyzed based on the stationary model,the nonstationary model of empirical mode decomposition(EMD)and the nonstationary model of optimal time-varying mean wind.The evaluated wind characteristics of plateau wind are compared with the field measurements for other sites and other types of winds,e.g.,typhoon.The results indicate that the turbulence intensities of fluctuating wind in winter are larger than those in the summer.In areas with similar topography,the turbulence intensities of fluctuating wind in plateau are greater than those in low-altitude areas,but are similar to those in some special topographies and wind fields such as fiord winds and typhoons.The calculation results of integral length scale are greatly influenced by the stationarity of wind speed samples,and the stationary model tends to overestimate the integral length scale.The fitted spectrum of fluctuating wind in the Tibetan plateau differs from the standard wind spectrum,and has larger high-frequency energy.Thus,it is important to pay attention to the differences between the characteristics of plateau fluctuating wind and those in low-attitude areas when performing wind-resistant design of buildings and structures.The non-stationarity of winds in plateau should be carefully considered to determine a reliable nonstationary wind model.

关 键 词：西藏 高原风 风场实测 脉动风特性 时变平均风速 

分 类 号：TU317[建筑科学—结构工程]