Numerical simulation of the Reynolds number effect on the aerodynamic pressure in tunnels

• Published in: Journal of wind engineering and industrial aerodynamics 2018-02, Vol.173, p.187-198
• Main Authors: Niu, Ji-qiang, Zhou, Dan, Liang, Xi-feng, Liu, Scarlett, Liu, Tang-hong
• Format: Article
• Language: English
• Subjects: Aerodynamic pressure; High-speed train; Passing by each other; Reynolds; Tunnel
• ISSN: 0167-6105; 1872-8197
• DOI: 10.1016/j.jweia.2017.12.013

With an increase in train speed, the aerodynamic effects caused by the train could escalate, especially for a train running in a tunnel. A number of large transient pressure waves are generated owing to the confined spaces within the tunnel, resulting in possible damage to the vehicle structure and the facilities in the tunnel. Therefore, it is necessary to study the aerodynamic performance of a train running in a tunnel. A scaled moving model test system was constructed to facilitate the simulation of the aerodynamic effects caused by a train running in a tunnel. In this study, the influence of grid density, calculation time step, and turbulence model on the pressure caused by the train entering the tunnel was analyzed, which is helpful for choosing suitable values of the aforementioned parameters to simulate the aerodynamic performance of the train in the tunnel. The impacts of Reynolds number effect on the distribution of the surface pressure and peak of pressure wave along the train, and the pressure waveform were also studied through numerical simulation on three scaled model trains (full scale, 1/8, 1/20, and 1/32 scaled). The findings aid in understanding the relationship between the Reynolds and pressure amplitude, and the results of the scaled test can be applied to a full-scale train. •Influence of grid density, calculation time step, and turbulence model on aerodynamic pressure in tunnel was analyzed.•Reynolds number effect in the case where two trains cross each other in a tunnel is greater than that of a single train.•With a decrease in the Reynolds, the mean amplitude of the fluctuating pressure increases.