Transient Pressure on Tube-Wall in Evacuated Tube Transportation:A Simulation and Experimental Study

The transient pressure on tube-wall,originated from a train running at ultra-high-speed in evacuated tube,was mathematically formulated with 3 D unsteady-compressible turbulence model,theoretically analyzed,numerically simulated in sliding mesh technique with FLUNT software and experimentally evaluated.The influence of the base-pressure,speed,blockage-ratio and ambient temperature on the transient pressure on tube-wall was investigated.The simulated results show that the base-pressure,speed and blockage-ratio all have a major impact.Specifically,little affected by temperature,the transient pressure linearly increases with an increase of the base-pressure,linearly decreases with an increase of the blockage-ratio,and is proportional to 2^nd power of speed.In generally,either lower base-pressure or higher speed or greater blockade-ratio produces larger fluctuation amplitude of the pressure on tube-wall.The simulated and measured results were in good agreement,except some discrepancy in response time and pressure fluctuation amplitude.