真空管道交通系统作为一种新型的交通运输模式，具有高速度、低能耗、环保性好、安全性能高等主要优点。Kantrowitz 极限问题是实现管道车辆跨音速高速运行的瓶颈。本项目通过研究真空管道车辆跨音速和超音速状态下外部绕流气动特征，建立以活塞风为特征的管道纵向流场理论模型，探索Kantrowitz极限现象的形成机理和演化过程，分析车身外型、车速和阻塞比等因素对Kantrowitz极限现象产生及管道内压力波传播特性的影响；在综合考虑系统安全运营、旅客舒适度、运行速率、建设成本和运营成本等因素的基础上，设计管道车辆理想气动形体和车身整体优化方法，揭示不同流场控制方法的减阻效应和能耗规律，寻求有效突破Kantrowitz极限的能耗最优途径，为我国真空管道交通系统设计、优化和建设提供理论依据和技术指导。

As a new type of transportation mode, the vacuum pipeline transportation system has the major advantages of high speed, low energy consumption, good environmental protection and high safety performance. The Kantrowitz limit problem is the bottleneck to realize the transonic speed of the vacuum tube vehicles. This project uses methods of theoretical analysis, numerical simulation and experimental verification to study the aerodynamic characteristics of the external flow around the vacuum tube vehicles under transonic and supersonic conditions, analyze the longitudinal airflow structure characterized by piston wind, explore the formation mechanism of Kantrowitz limit phenomenon and to analyze the influence of body shape, speed and blocking ratio on the generation of Kantrowitz limit phenomenon and the propagation characteristics of pressure wave in pipeline. In order to provide the theoretical basis and guide principles for the design, optimization and construction of vacuum pipeline transportation system in our country, various factors such as system safe operation, passenger’s comfort, operating speed, construction and operation cost are considered, the selection principle of vacuum pipeline system parameters and the optimization method for the whole body are established, the drag reduction effect and energy consumption law of different flow field control methods are revealed and the best way to break the Kantrowitz limit effectively is sought.