The Second International Conference on Railway Technology

Abstract

The entry of a high-speed train into a tunnel leads to a system of strong pressure waves inside the tunnel. These abrupt pressure changes go along with many disadvantages. The crucial parameter for the negative effects of the train-tunnel passage is the time derivative of the pressure and therefore the rise time of the pressure. A possible countermeasure is a hood equipped with several windows acting as an extended tunnel portal. The effect of the additional tunnel hood is highly influenced by the number and size of the portal windows, so the choice of the outflow area is very important. To get a better understanding of the effect of a vented tunnel hood experimental studies using an ICE3-model (scaled 1:25), a 10m-long model tunnel and a tunnel hood (both scaled 1:30) were performed at the tunnel-simulation facility G¨ottingen (TSG). The resulting blockage ratio was �Beta = 0:23. The pressure inside the tunnel was measured using pressure transducers and additionally the flow out of the portal windows was investigated using Particle Image Velocimetry. The studies result in an optimised tunnel-portal configuration. The pressure gradient can be reduced by about 60% compared to the gradient measured without extended portal.