【作者】 刘杰；

【导师】 李人宪；

【作者基本信息】 西南交通大学 ， 车辆工程， 2012， 博士

【摘要】 随着我国高速铁路的不断建设,时速200km/h和300km/h以上的列车较大规模的开通运营,列车的空气动力学问题越来越突出。高速运行列车交会时产生的压力波问题,列车交会产生的横向气动力问题,列车通过隧道时的压力波动问题等等,都会影响到列车运行的平稳性,进而影响旅客乘坐的舒适性。另一方面乘客对热舒适性的要求也越来越高。除了希望列车能够平稳运行以外,还希望车内热环境能一直保持舒适。这需要客室内有足够的新鲜空气供给,有合适的温度,合适的空气流动速度,合适的空气压力和湿度,较低的二氧化碳浓度。我国高速铁路的建设速度和高速列车的发展速度非常快,许多影响旅客乘坐舒适性的空气动力学问题还不很清楚。例如,两相向运行的列车发生交会时,通过列车产生的气动力(矩)会作用在对面列车上,而且这一气动力(矩)是正负交替变化的,作为激振源会引起车体不同方向的振动。因此需要研究会车产生的气动力(矩)的大小及其与车速、线间距和列车头型间的关系,以及气动力(矩)变化引起的车体振动过程,和会车对振动舒适性的影响程度。又如,高速空调客车是密封车体,只有新风入口与外界相通,车内热环境完全靠空调系统保证。什么样的空调系统能保证在我国广阔的地域空间条件下都能实现所希望的热舒适性,是需要认真研究的问题。此外会车时产生的气体压力波动或列车进入隧道时产生的气体压力波动,会通过列车空调系统的新风入口传到车内,使车内气体压力产生波动,造成乘客耳膜的不舒适。采用什么样的空调系统可以抑制外界压力波,使车内压力变化在人体感到舒适的范围内,也是需要认真研究的问题。我国发展高速列车的时间还很短,如何评价客室内乘坐舒适性的规范还没有建立。探讨适合我国国情的高速列车空调系统设计和车内热环境评价指标也是必须研究的课题。本文在“十一五”国家科技支撑计划子项目《高速列车车内流场控制技术》的支持下,对以下问题作了初步探讨：1.计算分析了不同车速、不同线路间距、不同列车头型条件下的会车压力波变化。得到了会车压力波幅随车速和线间距的变化规律,及压力波幅沿车体高度的分布情况。将不同头型列车的会车压力波进行对比,分析了不同头型列车的会车气动性能的优劣。计算了CRH2型动车组在常用的5m线间距下以不同速度会车时,空调系统新风入口处的压力变化,以便于进一步分析车内压力波动情况。2.分析了200-400km/h速度会车过程中作用在列车上的气动阻力、侧向力、升力、侧翻力矩、俯仰力矩和偏转力矩的变化过程,得到了会车时车厢所受气动力(矩)极值随车速和线间距的变化规律,以及不同车型对气动作用的影响。并进一步分析了气动力(矩)变化导致的车体振动过程,采用相关指标对会车时的振动舒适性进行了评价。3.计算分析了我国北方冬季和南方夏季环境条件下车内温度、风速、CO2体积浓度和相对湿度等热力学参数的分布情况,并根据流场参数和热舒适性指标对车厢内的热舒适性进行了评价,根据评价结果提出了空调客车室内流场参数的建议。4.根据明线会车及隧道内会车时新风入口的压力波,分析CRH2动车组采用一定压头风机抑制外界压力波动时车内的压力变化,根据压力变化幅度和压力降低率判定了风机对外界压力波的抑制效果。比较了一定外部压力波动条件下,固定频率风机和变频风机对车内压力变化的影响,通过对比车内压力波幅及波幅沿管道的降低过程,分析了两种风机对外界压力波抑制方法的区别,以及抑制效果的优劣。更多还原

【Abstract】 As the continual construction of high-speed railway, trains with speed of above200km/h and300km/h were extensively operated, and problems of aerodynamic turned to be more and more prominent. Pressure pulse and lateral aerodynamic force as trains passing by each other, and pressure wave as trains traveling through tunnel, will influence stability of train and riding comfort of passengers.At the same time, passengers’demand of comfort becomes higher and higher. Passengers want trains running stably and comfortable thermal environment. This will need enough fresh air, and appropriate temperature, air speed, pressure, humidity, and carbon dioxide concentration in compartment. In China construction of high-speed railway and development of high-speed train are so fast, but a lot of aerodynamic problems which influence passengers’riding comfort are not very clear. For example, when two trains are running by each other, aerodynamic forces (moments) produced by passing train will act on observing train, then become excitation source and induce vibration of train bodies in many directions. So it is necessary to study on values of aerodynamic forces (moments), their relations with train speed, track distance, and locomotive shape, and their effect on passengers’vibration comfort. On the other hand, high-speed air-conditioned train is airtight, only fresh air inlet is connected with external atmosphere, therefore air-conditioning system controls thermal environment in train completely. So what kind of air-conditioning system can realize thermal comfort hoped at the vast expense of our country is a problem, which needs to be seriously studied. Pressure-waves produced as trains passing by each other and traveling through tunnel can transfer into compartment via fresh air inlet, and make pressure indoor to change, and then induce uncomfortable feeling of passengers’ears. So what kind of air-conditioning system can resist external pressure-waves and make passengers comfortable is another problem need to be seriously studied. High-speed train is being developed for a so short time in China, and there is no standard to evaluate thermal comfort in compartment. The design of air-conditioning system and evaluation standard of thermal environment in high-speed train are necessary to be studied.At the assistance of National Science&Technology Support sub-Project during the11th five-year plan period 《control technology of air flow field in high-speed train》, preliminary study work was made about following problems:1. Pressure-pulses as trains passing by each other were analyzed in conditions of various speeds, various track distances, and various shapes of locomotive. The variation regularity of the pressure-pulse amplitude along with speed and track distance was found, and the distribution of amplitude along with height of train body was obtained. Aerodynamic characteristic as trains passing by each other was analyzed from comparing pressure-pulse of different shapes of locomotive. Finally, the pressure-pulses at fresh air inlet of CRH2train were obtained, preparing to calculate pressure-wave in train.2. The changes of air resistance force, side force, vertical force, capsizing moment, pitching moment, and yawing moment, were analyzed as trains passing by each other at speed of200km/h-400km/h. Variation regularities of every aerodynamic force (moment) peak along with speed and track distance were obtained. Train-shape effect on aerodynamic forces (moments) was analyzed. Then train body vibration induced by aerodynamic force (moment) was analyzed, and passengers’ vibration comfort was evaluated as trains passing by each other.3. The distributions of temperature, air velocity, CO2volume concentration, and relative humidity in compartment were calculated in summer of south and winter of north. And the thermal comfort was evaluated by air flow field indexes and thermal comfort indexes. Then based on the evaluation, some suggestions were given.4. According to the pressure-pulse at fresh air inlet as trains passing by each other in open air and in tunnel, the pressure-change in compartment was calculated when the train uses high property fan in air-conditioning system to resist the external pressure-pulse. The resistance effect was judged based on amplitude and reducing rate of pressure-change indoor. Effect of two kind of fan on pressure-change indoor was compared when external pressure-pulse is constant. The difference between frequency-fixed fan and frequency-convertible fan in resistance way and resistance result of pressure-pulse was analyzed, according to the comparison of pressure amplitude indoor and reducing process of amplitude along pipes.更多还原