列车通过分岔隧道的气动效应研究

Aerodynamic effects of trains circulating through a bifurcated tunnel

长大铁路隧道受特殊地质条件影响可采用分岔隧道建造。然而,列车高速穿越这种复杂构型的隧道时所引起的空气动力学效应尚不清楚。为此,本文采用三维、可压缩、非定常的雷诺时均模型,模拟研究了高速列车从不同方向通过分岔隧道时引起的气动效应。研究内容主要包括入口隧道结构为单线隧道(STE)和双线隧道(DTE)两个运行环境下的车体表面和隧道壁面的压力波动、列车气动力和周围流场特征等。研究结果表明,相比STE场景,DTE场景下车体表面和单线隧道壁面的压力峰峰值更大,并且气动阻力能耗也更大,头车的平均阻力增大19.2%。然而,STE场景下列车的侧向力波动更剧烈,其峰值相比DTE场景增加26%。本文的研究发现可为特殊铁路隧道的设计和建造提供有价值的空气动力学参考。

In practice,bifurcated railway tunnels are occasionally employed in the construction of long tunnels due to specific geological reasons.However,the aerodynamic behaviors of trains moving through such complex tunnels are not yet fully understood.To address this issue,this study analyzes the aerodynamic interactions produced by a high-speed train moving through a bifurcated tunnel in different directions.A three-dimensional,unsteady,compressible method based on the RNG k-εturbulence model is used to simulate the train motion in the tunnel.Additionally,the simulation algorithm is validated by comparing the data with full-scale experimental results.The analysis includes the examination of aerodynamic loads and transient pressures on both train surface and tunnel wall.The results indicate that the maximum peak-to-peak pressures on train surface and the the single-track tunnel wall of DTE(double-track tunnel as entry)scenario are larger than that of STE(single-track tunnel as entry).Moreover,for the DTE scenario,the energy consumption of the train moving through the tunnel is significantly higher,and the average drag of the leading vehicle is increased by 19.2%compared with the STE.However,the side force of the leading vehicle for the STE is 26%higher than that of the DTE.The research findings presented in this paper can serve as a valuable aerodynamic reference for the design and construction of specialized tunnels.