文档介绍：本科毕业论文
院系电子科学与工程系
题目高速列车进入隧道产生的微压波及其控制研究
年级专业声学
班号学号
学生姓名
指导教师职称
论文提交日期
摘要
高速列车进入隧道产生的压缩波传播到遂道出口时,会向出口外辐射一低频脉冲波,这种脉冲波产生的爆炸声可达140~150dB甚至更高的声压级,对周边环境造成严重危害,这种低频脉冲波被称为“微气压波”。本文以声波方程为基础,根据无扰动边界假设,对高速列车在隧道内产生的压缩波进行计算,根据理论结果作了数值模拟,通过与文献中理论和数值模拟结果的对比,显示出了很好的一致性。在此基础上,根据微气压波与压缩波的梯度成正比的性质,提出两种有源控制方法,并对间接控制方法作了理论分析和数值模拟,结果显示了有源控制的可行性和高效性。对于直接控制方法,提出了控制要点和实现方法。最后设计了微压波产生、观测和有源控制实验。
Abstract
When pression wave induced by a high-speed train entering a tunnel propagates to the tunnel exit, a low-frequency pulse wave is radiated. The sound level of explosions of this pulse, which causes serious damages to the surrounding environment, is up to 140 ~ 150 dB even higher. This low-frequency pulse is called "micro-wave pressure". Based on acoustic equation and the undisturbed boundary assumption, pression wave generated by a high-speed train entering a tunnel is calculated in this paper. Numerical simulation is then made according to theoretical results. The contrasts with those results in the literature show a good agreement. On the basis of the conclusion—the micro-wave is proportional to the pressure gradient of pression wave, two active control methods are proposed. The theoretical analysis and numerical simulation are made according to the indirect control method and the results show the feasibility and efficiency. For direct control method, the key points of the method and the general implementation program are put forward. Finally, the experiments of the generation, observation and active control of the micro-pressure waves are designed.
目录
摘要 i
Abstract ii
第一章引言 1
1
1
3
4
第二章理论推导和数值模拟 6
6
10
11
第三章微压波有源控制 12
12
13
14
第四章结束语 17
参考文献 18
致谢 20
第一章引言

当高速列车通过隧道时,列车与隧道内的空气之间发生强烈的相互作用,诱发一系列空气动力学效应,较突出的就是洞内列车行车阻力增大、在隧道内部形成很大的瞬变压力,这种压力变化以压缩波的形式接近声速在隧道内传播,当压缩波传播到隧道出口时,大部分能量以膨胀波的形式向隧道内反射回去,造成隧道内压力波动,影响乘车舒适度;同时也向外辐射出一低频脉冲波,这种脉冲波产生的爆炸声可达140~150