400km/h高速列车头型对隧道初始压缩波影响初探

Preliminary Study on the Effect of Nose Shape of 400 km/h High Speed Trains on Initial Compression Waves in Tunnel

采用重叠网格方法,基于三维非定常可压缩的N-S方程和SST k-w湍流模型,探索时速400 km/h高速列车头型对隧道初始压缩波的影响。针对目前国内研发的某型CR450动车组,本文研究2个鼻长均15 m和1个鼻长22 m的拟议新头型,分析在我国现有隧道条件下3种不同头型列车以400 km/h驶入时产生的初始压缩波基本特性;最后分析了不同车速(350 km/h、400 km/h、450 km/h)驶入隧道时对初始压缩波最大压力梯度值的影响。对比距隧道入口72 m处隧道内测点的压力与压力梯度值,结果表明:2个鼻长15 m头型列车对应产生的初始压缩波波形和最大压力梯度值基本一致;相比于鼻长15 m头型,鼻长22 m头型对应产生初始压缩波波形有着明显区别,且最大压力梯度值较之降低约27%;列车速度越高,对应产生初始压缩波最大压力梯度值则越大,但缓冲结构的缓解作用越不明显。研究结果对新一代高速列车头型设计和气动性能比选具有实际性的参考价值。

An overlapping grid method is used to explore the effect of nose shape of 4oo km/h high-speed trains on the initial compression wave in tunnels based on the three-dimensional non-constant compressible N-S equations and the SST k-w turbulence model.For a certain type of CR450 train developed in China at present,this paper studies the proposed new nose shape with two nose lengths of 15 m and one nose length of 22 m,and analyzes the basic charac-teristics of the initial compression wave generated by the three different nose shapes of trains entering the tunnel at 400 km/h under the existing tunnel conditions in China;and finally the effect of different speeds(350 km/h,400 km/h,45o km/h)on the value of the maximum pressure gradient of the initial compression wave as the train enters the tun-nel is analyzed.Comparison of the pressure and pressure gradient values at 72 m from the tunnel entrance shows that:The initial compression waveforms and the maximum pressure gradient values generated by the two trains with 15 m nose lengths are basically the same;Compared with the 15 m nose lengths,the initial compression waveforms generated by the 22 m nose lengths are significantly different,and the maximum pressure gradient values are reduced by 27%;The higher the train speed,the higher the maximum pressure gradient value corresponding to the initial compression wave,and the less obvious the mitigating effect of the hood,The results of the study have practical ref-erence value for the design of new generation of high-speed train nose shape and aerodynamic performance compari-son.