对高速列车由横风环境驶入隧道过程中流场的非定常、可压缩以及湍流等特性， 建立了隧道 －列车 －空气三维 CFD 数值模型，分析了列车驶入隧道时各节车厢的气动荷 载瞬态变化特征及对应的车厢运行姿态变化，并从流场角度揭示了其变化机理，最后探讨 了气动荷载对车厢的冲击效应． 主要结论如下: ( 1) 当列车由横风环境驶入隧道时，各节 车厢的5 项气动荷载均表现出显著的突变特征，相应地各节车厢均会呈现瞬间偏转以及 瞬间“点头”等行为;( 2) 车厢两侧压差在纵向上的巨大差异是导致车厢横向力和倾覆力 矩的突然卸载以及偏航力矩骤增的根本原因; ( 3) 横风是导致气动荷载对车厢冲击强度 显著升高的主要因素;( 4) 头车的安全系数是控制整列车运行安全性的关键

A 3D CFD numerical model of tunneltrain-air was built to analyze the transient change characteristics of the aerodynamic loads of each carriage when a HST enters tunnel and the corresponding change of the running postures of each carriage，considering the unsteady compressible turbulent characteristics of the flow field when a highspeed train ( HST) enters into tunnel． The corresponding change mechanisms were uncovered from the perspective of flow field． The impact effect of aerodynamic loads on the carriage was discussed． The main conclusions are as follows: ( 1) The five aerodynamic loads of each carriage show remarkable sudden change characteristics，and accordingly，all carriages show instantaneous deflection and‘nodding’and other behaviors． ( 2) The great difference in longitudinal pressure difference between the two sides of the carriage is the fundamental reason of the sudden unloading of side force and rolling moment and the sudden increase of yawing moment． ( 3) Crosswind is the main factor that causes the impact strength of aerodynamic loads on the carriage to rise remarkably． ( 4) The safety coefficient of the head carriage is the key to control the traffic safety of the whole train．