Effect of the cavity edge topology on the aerodynamic noise of a pantograph in high-speed train

Abstract This research investigates the aerodynamic flow behavior and noise contribution of various cavity configurations designed to reduce aerodynamic noise in a simplified DSA 350 SEK pantograph model, scaled to 1/10. The cavities are classified into dual-shape and single-shape designs, with four distinct models (concave–convex, convex–concave, convex, and concave) analyzed in three sizes. A base cavity with a sloped edge at θ = 80° serves as a reference for comparison. Computational fluid dynamics (CFD) simulations are performed to evaluate flow characteristics, followed by the Ffowcs Williams and Hawkings (FW–H) aeroacoustic analogy is applied to estimate far-field sound pressure levels (SPLs). The results demonstrate that the convex-edged cavity improves aerodynamic performance by reducing the root-mean-square (RMS) drag and lift coefficients from 0.026 to 0.023 and from −0.06 to −0.038, respectively, and lowering the mean drag and lift coefficients from 0.23 to 0.18 and from −1.3 to −0.85, relative to the base cavity, thereby mitigating both steady and unsteady aerodynamic forces. Noise predictions, obtained from receivers positioned 2.5 m away in the scaled model at a train speed of 300 km/h, show reductions in noise levels from 81.9 to 77.3 dB at the top receiver and from 68.4 to 63.1 dB at the side receiver. Incorporating the pantograph into the optimal and base cavity designs reveals further aerodynamic improvements, with the optimal cavity reducing the pantograph’s aerodynamic noise by 2.7 dB(A) in total sound power. Sound pressure levels decrease by 2.3 dB(A) at the top receiver and 1.8 dB(A) at the side receiver compared to the base cavity.