速度600km/h单列磁浮列车通过隧道时压力载荷特征研究

Research on Pressure Load Characteristics of 600 km/h Single Maglev Train Passing Through Tunnel

列车由明线高速行驶突入隧道的瞬间,列车周围的空气流动空间骤然变小,车头前方的空气受到压缩压力急剧升高,形成初始压缩波,并以当地声速向隧道出口端传播。当列车尾部进入隧道时,由于列车尾部占据的空间得以释放,空气压力突然降低,形成膨胀波。压缩波与膨胀波传播到隧道端口被反射为具有相反性质的波,两者相互叠加,导致隧道内产生剧烈的压力波动。文章采用一维可压缩非定常不等熵流动模型和广义黎曼变量特征线方法对速度600 km/h单列磁浮列车通过隧道时压力波问题进行数值模拟研究,通过对隧道内压力变化形成原理的分析,揭示了隧道内气动载荷的变化特性,以及车体表面压力幅值和隧道长度、列车速度、阻塞比之间的变化规律。研究结果可为高速磁浮列车通过隧道时洞内和车体气动载荷设计提供数据参考。

In an instant,when the train enters the tunnel from the open line,the air flow space around the train suddenly becomes smaller,and the air in front of the train is compressed and the air pressure increases sharply,forming an initial compression wave,which propagates to the tunnel exit at the local sound speed.When the rear of the train entered the tunnel,as the space occupied by the rear of the train was released,the air pressure suddenly dropped,forming an expansion wave.Compression waves and expansion waves propagated to the tunnel port and were reflected as waves with opposite properties.The two superimpose on each other,resulting in severe pressure fluctuations in the tunnel.The one-dimensional unsteady compressible non-homentropic flow model and generalized Riemann variable characteristic line method were used to numerically simulate the pressure wave of the maglev train passing through tunnel at a speed of 600 km/h.Through the analysis of the formation mechanism of pressure changes in the tunnel,the changing characteristics of the aerodynamic load in the tunnel was revealed,as well as the changing law between the amplitude of the surface pressure of the car body and the length of the tunnel,train speed,and blocking ratio.The research results could provide data reference for the design of aerodynamic loads in the tunnel and car body when the high-speed maglev train passes through the tunnel.