Research On Aerodynamic Resistance And Noise Of Mechanical External Windscreen Between Passenger Vehicles

Abstract

Aiming at the problems of aerodynamic resistance, noise, and operation safety of rubber windshields, a new mechanical external windshield for the train was designed. Based on the model of three car high-speed train, the frequency spectrum characteristics of aerodynamic noise were analyzed under 300 km/h, 400 km/h, and 500 km/h working conditions, and the aerodynamic characteristics and flow field distribution of mechanical external windshield were compared with those of the existing windshields. The results show that under the same speed, the pressure distribution of the mechanical external windshield was relatively gentle, and the velocity loss of the vortex generated in the cavity was small. The radiated noise from the dipole sound source on the train surface decreased with the increase of the distance from the vehicle body. Also, as the frequency increased, the noise sound pressure presented a downward trend, and the distribution tended to be uniform gradually. In directivity, the sound pressure on both sides of the windshield has a certain symmetry. The sound pressure fluctuation was consistent with the frequency change, and the maximum sound pressure occurred at the position where the curvature change at the upper end of the windshield was the largest. The research results in this paper can provide some reference for the design of the train windshield structure and the reduction of train resistance and noise.

Keywords

• high-speed trains
• external windshields
• aerodynamic resistance
• aerodynamics noise