Effect of non-fully enclosed windshield on aerodynamic and acoustic behaviors of high-speed train.

Abstract

In the design of the outer windshield of high-speed trains, the non-fully enclosed windshield structure is widely used. Based on the cavity flow-induced vibration theory and FW-H acoustic equation, the flow field and acoustic characteristics of three high-speed train models with different windshield configurations are compared and analyzed. Numerical simulations were validated by full-scale experiments. The results show that the noise generated from the windshield area is mainly composed of low-frequency peak resonance noise and broadband turbulent noise. A typical Helmholtz resonator cavity is composed of inner and outer windshields. The position and number of windshield openings affect the airflow structure inside the windshield and the train wake. In addition, the hole as a potential aerodynamic noise source determines the vortex shedding and cavity resonance frequency, resulting in different acoustic feedback. The energy of windshield noise is mainly concentrated in the low frequency range below 400Hz. The windshield configuration of M1 and M3 shows tonal noise characteristics, while the M2 model eliminates the generation of low-frequency resonance noise. Compared with the M1 and M3 models, the noise generated by the windshield and the whole train of the M2 model is reduced by 3.83 dB and 1.77 dB, respectively.