高速列车通过隧道时诱发车厢内压力波动的数值分析

在假定列车车体为均匀多孔车体的基础上,根据一维可压缩非定常不等熵流动理论与广义黎曼特征线法,研制了高速列车通过隧道过程中诱发车厢内外空气瞬变压力耦合的计算方法和计算程序。其中,基于热力学第一定律的“充排法”建立了车厢内压力波动的计算方法,并成功地将该方法推广应用于隧道内会车条件下车厢内压力的计算分析中。通过与国外试验数据的验证表明了本文计算方法与程序的正确性,为准确合理地计算高速列车通过隧道时诱发车厢内瞬变压力提供了可靠的分析工具。

Numerical Analysis of Transient Pressures inside High Speed Passenger Trains through Tunnels

When trains pass through a tunnel, the pressure waves generated outside the trains propagate into the interior. If sufficiently strong, the waves can cause passengers to suffer aural discomfort. One of the alleviation methods is to seal or partially seal the trains. In order to assist in the design of sealed trains it is useful to investigate the internal pressures inside passenger trains . This paper uses an approach in which the train is modeled as a uniformly porous body. The external pressure waves are simulated using the one-dimensional unsteady compressible non-isentropic flow and the method of characteristics expressed with generalized Riemann Variables. A mass transfer term is incorporated in the equation of one-dimensional unsteady fluid flow to model the effect of flow through the sides of the train .The pressures inside the train are established using a "filling and emptying" analysis based on the first law of thermodynamics. Leakage flows are determined from the pressure differences in the air flow space of the train and tunnel by treating the pores as small orifices. In this paper the above methods can be used to simulate pressure waves inside and outside the trains successfully when two trains cross in a bore tunnel. The calculated results show that the numerical prediction method and model are reasonably based on comparisons with foreign measured pressure waves. The paper presents a series of predictions which show the effect of porosity on internal and external pressure waves.