Aerodynamic noise from vehicles on the Yamanashi Maglev Test Line

Abstract

This paper is a report about aerodynamic noise from Maglev vehicles running at an ultra high speed. Maglev running tests have been carried out on the Yamanashi Maglev Test Line and 550 km/h was recorded in December 1997. The noise produced when Maglev vehicles run at high speed consists of almost only aerodynamic noise because of the levitated running of Maglev vehicles. Two types of nose shapes were developed for Yamanashi test cars in order to considerably reduce air drag and aerodynamic noise. The noise measured when Maglev vehicles running on the viaduct at the velocity of 500 km/h will be reported in this paper. Also the rate of increase of noise to velocity and the source of noise of running Maglev vehicles will be reported. In general, it is known that when a high-speed train enters a tunnel, a compression wave is generated ahead of the train and a pulse wave radiates from the exit of the tunnel, and an air pressure booming noise is generated in some cases. This air pressure booming noise is successfully suppressed by setting a hood at the tunnel entrance in this test line.