Railway equivalent noise sources definition: ESM implementation and optimization

Estelle Bongini , Hugo Marcus

Within the scope of a better integration of railway system in environment, prediction of trains pass-by noise is a growing concern for railway operators. SNCF has therefore developed the software VAMPPASS dedicated to pass-by noise simulation. The synthesis method implemented in VAMPPASS requires the definition of equivalent noise sources representative to real noise sources on the train. Equivalent sources definition is mainly based on experimental characterization. Measurement methods based on 1D-array devices have been optimized on a real train and post-processing methods have been developed for identifying mono-multipole equivalent sources, defined with the spherical harmonics formalism. This kind of method needs a heavy optimization process, applied on several parameters. It can imply large error coefficients on the radiated pressure field. The present study aims to investigate the potential of Equivalent Source Method (ESM, a transfer matrix based method) to fulfil the requirements of VAMPPASS. In the first chapter, the ESM basis is presented. The second chapter is dedicated to the ESM implementation on a train scale model, with multi-monopoles or multi-dipoles equivalent sources. In the third chapter, improvements of the ESM for VAMPPASS requirements are discussed: genetic algorithm method has been used to optimize the equivalent noise sources locations.

Mots clés: equivalent noise sources; ESM; railway noise

Domaines: Acoustique [physics.class-ph]

Estelle Bongini, Hugo Marcus. Railway equivalent noise sources definition: ESM implementation and optimization. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810783⟩