为了探索列车运行时真空管道交通(ETT)系统中热压耦合的气动特性,建立EET系统三维数学模型及物理模型,对系统的运行特性进行了仿真,结果表明:列车的最前端驻点处出现压力的最大值,车尾卡门涡街处出现压力的最小值。但由于该系统结构尺寸巨大,计算耗时长,工作量大,因此基于相似准则,结合ETT系统的运行特点,推导了ETT系统的相似准则方程,并在此基础上对系统的运行特性进行了研究,结果表明:在相似理论指导下,当小尺寸模型时,系统的压力场与原模型的压力场分布情况相似,最高和最低压力值仍然出现在列车的最前端驻点和车尾卡门涡街处,压力梯度变化云图相似,随着列车运行速度的增加压差呈抛物线式增长,最高温度同样呈抛物线式增长趋势,数值仿真结果与原模型尺寸的结果相比,压力场的最大相对误差为0.56%,温度场的最大相对误差为0.16%,均可以接受,因此在相似理论指导下,可以有效缩短ETT系统的数值计算周期。
The aerodynamics characteristics, involving thermal-pressure coupling of the maglev train running in evac- uated tube transportation (ETT) system, were mathematically modeled with the realistic and much reduced size,theoreti- cally analyzed based on similarity theoretics, and numerically simulated with software Ansys. The impact of the train-veloc- ity on the temperature and pressure distributions was investigated. The simulated results with the size-reduced model show that the highest and lowest pressures exist at the stagnation point on the nose and at Karman vortex-street on the tail of the maglev-train, respectively, and that the grayscale plots of the temperature and pressure fields resemble those simulated with the realistic model. As the velocity increases, the pressure difference and highest temperature increase quadratically. The largest relative discrepancies of the pressure and temperature fields, simulated with the realistic and size-reduced models, were estimated to be 0.56% and 0.16%, respectively. We suggest that the size-reduced model may outperform the realistic one because of a significant reduction of computation workload and the high accuracy.