Model experiments for optimizing the height of tunnel-hood windows for MPW reduction

Abstract

The tunnel-hood effect should be improved to increase the maximum speed of the Shinkansen, while avoiding the serious noise and vibration due to micro-pressure waves (MPWs) from the tunnel portals. The longitudinal positions of windows on conventional hoods are usually optimized. This study used model experiments to investigate the optimal height of windows on the tunnel hoods. The obtained results showed that the hoods with optimized-height windows can reduce the MPWs to the same value as conventional hoods. In addition, the height-optimizing procedure is very simple, compared to the position-optimizing procedure, and the optimized-height can be easily and certainly obtained.