通风路基通风管管内空气流动特性研究  

Study of air flow characteristics in ventilation duct of ventilated embankment

作　　者：李晓宁[1,2] 俞祁浩[1] 游艳辉[1] 郭磊[1,2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《冰川冻土》2016年第5期1300-1307,共8页Journal of Glaciology and Geocryology

基　　金：中国科学院STS项目(HHS-TSS-STS-1502);冻土工程国家重点实验室重点项目(SKLFSE-ZY-17);国家科技支撑计划项目(2014BAG05B03)资助

摘　　要：基于青藏高速公路试验工程的实测资料,利用数值模拟系统分析了通风路基通风管内的空气流动特性和变化规律.研究表明,当外界环境风速一定时,通风管内不同区域流动特征显著不同,表现为较为明显的三段性:在入口扰动区段,管内空气紊流强度最大;中部为完全湍流区,紊流强度最弱;出口射流影响区的紊流强度介于入口扰动区和完全湍流区之间.随着外界环境风速的增加,管内空气流速相对环境风速增加的量值随之增加,总体呈现非线性快速增加的趋势;入口扰动响应的长度和紊流强度增加最显著;尾部射流影响区由于受到空气流动惯性等因素影响,其长度以非线性加速减小,其空气运动轨迹的振动幅度以非线性加速提高.管内各区域空气流动特性的不同是造成通风管不同部位局部换热量差异的根本原因,这些流动特性的存在进一步叠加,或是导致通风管路基阴阳坡效应的重要因素之一.Based on the data of the Tibetan Plateau highway test project of the Chinese Academy of Sciences, air flow characteristics in the ventilation duct and variation are studied by numerical simulation. The study demonstrates that air flow characteristics are significantly different from place to place when the ambient wind velocity reaches a certain value, showing three sections obviously, i. e. , the inlet turbulence section with strong turbu- lence intensity, the middle section with fully developed turbulent of weakest intensity, and the jet-influence section with the turbulence intensity in between the two sections before. With increase of the ambient air velocity, the air velocity within the duct increase nonlinearly. At the same time, the length and the intensity of turbulence activity in the inlet disturbed section increases significantly. In the jet-influence section, because of the influence of the air flow inertia, the length reduces by a nonlinear acceleration, and the vibration amplitude of air motion trajectory accelerates nonlinearly. The diversity of the air flow characteristics in different sections of the ventilation duct is the basic reason for the different in local heat transfer flux. The existence and further superposition of these flow characteristics would become an important factor for developing the different between the south-faced slope and north-faced slope.

关 键 词：通风管 流动特性 数值模拟 紊流强度 局部换热量 

分 类 号：TU752[建筑科学—建筑技术科学]