Influence of high-speed maglev train speed on tunnel aerodynamic effects

When a high-speed maglev train enters a tunnel, the pressure around it rises and changes quickly. This may lead to serious damage of the train and tunnel structures. With increases of train speed, up to 600 km/h, this issue will become worse. In this study, the three-dimensional, compressible, unsteady, k-ϵ two-equation turbulence model and sliding grid technologies were used to study the effect of train speed on the pressure waves induced by a maglev train passing through a tunnel. The numerical simulation method used was validated against results from moving model tests and semi-empirical formulations. The maglev train modelled was specified to pass through a 2 km tunnel with speeds in the range from 400 km/h to 600 km/h. The surface pressure distribution of the train and tunnel were found and are discussed. The transient pressures on the maglev train and tunnel surface are shown to have a significant relationship with the train speed. Generally, the maxima of the train surface pressures follow the power law relationship with an exponent of 2.35 to the train speed, while for the tunnel surface pressure, an exponent of 2.46 is obtained. The gradient of the initial compression wave at the tunnel entrance follows a power law relationship with an exponent of 3.51 to the train speed, while at the exit this rises to an exponent of 4.99. The amplitude of the micro-pressure wave follows a power law relationship with an exponent of 5.00 to the train speed. Having such data will provide essential support for the design of both the maglev train and tunnel.