Aeroacoustics source identification and analysis of a high-speed pantograph

Thoroughly comprehending pantograph noise mechanisms and characteristics is crucial for its low noise design, and high-resolution aeroacoustics source identification is the prerequisite for deepening these comprehensions. This study develops an aeroacoustics source identification method based on the integral formulation of the Ffowcs Williams–Hawkings equation and demonstrates its application in pantograph noise analysis. High-resolution distributions of near-field dipole and quadrupole sources of the pantograph are determined by using flow field data obtained from an improved delayed detached eddy simulation (IDDES). Then, combined with a detailed pantograph flow-field analysis, the formation mechanism of aeroacoustics sources is discussed. The IDDES flow-field data is also utilized for far-field noise calculation. The far-field noise results are correlated with the aeroacoustics source identification results, and the radiation characteristics of the pantograph aerodynamic noise are also explained. Finally, based on the aeroacoustics source identification and analysis, some guidelines for low-noise design of the pantograph are summarized.