Open Access

ARTICLE

The Influence of an Imposed Jet and Front and Rear Wall Modification on Aerodynamic Noise in High-Speed Train Cavities

Yangyang Cao, Jiye Zhang^*, Jiawei Shi, Yao Zhang

State Key Laboratory of Rail Transit Vehicle System, Southwest Jiaotong University, Chengdu, 610031, China

* Corresponding Author: Jiye Zhang. Email:

(This article belongs to the Special Issue: Computational Fluid Dynamics: Two- and Three-dimensional fluid flow analysis over a body using commercial software)

Fluid Dynamics & Materials Processing 2025, 21(5), 1079-1098. https://doi.org/10.32604/fdmp.2025.060429

Received 31 October 2024; Accepted 17 January 2025; Issue published 30 May 2025

Abstract

The pantograph area is a critical source of aerodynamic noise in high-speed trains, generating noise both directly and through its cavity, a factor that warrants considerable attention. One effective method for reducing aerodynamic noise within the pantograph cavity involves the introduction of a jet at the leading edge of the cavity. This study investigates the mechanisms driving cavity aerodynamic noise under varying jet velocities, using Improved Delayed Detached Eddy Simulation (IDDES) and Ffowcs Williams-Hawkings (FW-H) equations. The numerical simulations reveal that an increase in jet velocity results in a higher elevation of the shear layer above the cavity. This elevation, in turn, diminishes the interaction area between the vortices produced by jet shedding and the trailing edge of the cavity wall. Consequently, the amplitude of pressure pulsations on the cavity surface is reduced, leading to a decrease in radiated far-field noise. Specifically, simulations conducted with a jet velocity of 111.11 m/s indicate a remarkable noise reduction of approximately 4 dB attributable to this mechanism. To further enhance noise mitigation, alterations to the inclination angles of the cavity’s front and rear walls are also explored. The findings demonstrate that, at a constant jet velocity, such modifications significantly diminish pressure pulsations at the intersection of the rear wall and cavity floor, optimizing overall noise reduction and achieving a maximum reduction of approximately 6 dB.

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Keywords

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