High-Speed Vehicles in Low-Pressure Tunnels—Influence of Choked Flows

The aerodynamics of high-speed vehicles in evacuated tunnels is studied with particular reference to the consequences choked flow conditions at tails vehicles. It shown that this has a dominant influence on overall (pressure, temperature, velocity). Together need for tunnel system be closed, high speeds cause aerodynamic behaviour differ greatly from conventional railway tunnels. A key purpose paper assess relative importance large range parameters and, clarity, completed by focussing single vehicle closed both ends. Consideration then given interactions between more than one and twin-tube configuration which occur moving opposite directions. closes brief mention system-dependent matters considered addition generic investigated herein.