基于壁面射流的下击暴流非稳态风场大涡模拟  

Large Eddy Simulation of Unsteady Downburst Outflow Based on Wall Jet Model

作　　者：钟永力 晏致涛[1,2] 王灵芝 游溢[1,3] ZHONG Yongli;YAN Zhitao;WANG Linzhi;YOU Yi(School of Civil Engineering,Chongqing University,Chongqing 400045,China;School of Civil Engineering and Architecture,Chongqing University of Science and Technology,Chongqing 401331,China;State Grid Xinjiang Electric Power Company Electric Power Research Institute,Urumqi 830011,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆科技学院建筑工程学院,重庆401331 [3]国网新疆电力公司电力科学研究院,新疆乌鲁木齐830011

出　　处：《西南交通大学学报》2018年第6期1179-1186,共8页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(51478069;51178489);重庆市科委资助项目(CSTC2017JCYJB0210)

摘　　要：为研究边界层风洞中下击暴流大缩尺比试验的可行性,基于冲击射流和壁面射流模型,采用大涡模拟方法,分析了静止和移动下击暴流的风场特性;通过与Wood模型、Oseguera模型、Victory模型以及经典壁面射流实验对比,验证了采用冲击射流和壁面射流模型在模拟稳态下击暴流出流段的一致性和有效性;在壁面射流模型入口处引入3种速度函数,模拟了下击暴流非稳态风速时程.研究结果表明:与冲击射流一样,无协同流壁面射流能够有效地模拟静止下击暴流的稳态出流段;当冲击射流平移速度为出流速度的15%时,其最大水平风速较静止冲击射流增大了15.8%;协同流速度为射流速度的19.2%时,其最大风速较无协同流壁面射流增大了16.9%,带协同流壁面射流能够有效地模拟移动下击暴流;提出的速度入口函数模型作为壁面射流入流条件,能够较为真实地模拟出Andrews AFB下击暴流非稳态风场.The feasibility of a large-scale experiment for downburst in a boundary layer wind tunnel was investigated. Large eddy simulation （LES） was employed to investigate the characteristics of stationary and travelling downburst using the impinging jet and wall jet methods, respectively. The velocity profiles from LES were compared with those obtained from the Wood model, the Oseguera model, the Victory model, and the classical wall jet experiment to verify the reasonableness of the two methods. Then, three time functions of the inlet velocity were used to obtain similar time series of the full-scale data. The results show that the fullydeveloped velocity profiles of the wall jet cohere with those of the three theoretical models and the classical wall jet experiment. When the translational velocity is 15% of the impinging jet velocity, the maximum horizontal wind speed increased by 15.8% compared to that of the stationary impinging jet, while when the velocity of co- flow is 19.2% of the wall jet velocity, the maximum horizontal wind speed increased by 16.9% compared to that of the wall jet without co-flow. The stationary downburst can be appropriately simulated using the wall jet model without co-flow, while the travelling downburst can be effectively simulated using the wall jet model with co-flow. The results from large eddy simulation （LES） and data obtained from Andrews AFB downburst are in good agreement. The unsteady characteristics of downburst outflow can be perfectly reproduced by the time functions of the velocity inlet.

关 键 词：下击暴流 壁面射流 冲击射流 数值模拟 风速时程 

分 类 号：TU311[建筑科学—结构工程]