Sound level prediction in open-spaces: implementation of diffraction in RAYPLUS software

Patrick Chevret (1) , Jacques Chatillon (1)

1 INRS ( Vandoeuvre lès Nancy) - Institut national de recherche et de sécurité (Vandoeuvre lès Nancy)

This study addresses the problem of diffraction by screens in open-plan offices. A numerical model, based on a ray-tracing method, was implemented. The initial model used was a piece of software whose purpose was to predict sound levels in industrial premises. Diffraction was introduced into the model via the Uniform Theory of Diffraction (UTD). For the purposes of validation, a campaign of tests was conducted in a semi-anechoic chamber. A first series of measurements of diffraction by a single screen and by a low-divider partition on a double desk made it possible to validate the experimental conditions through comparisons with the UTD. In the same experimental context, the predictions of the octave band spectra with the modified model were of good accuracy. In a second series of measurements, a removable ceiling was suspended above the double desk. The acoustic field behind the low divider was then made up of a mixture of the field diffracted by the low divider and of the field reflected by the ceiling. The results of the comparisons between calculations and measurements in this unitary configuration show that the modified model can be an excellent tool for predicting sound levels in an open-plan office.

Mots clés: ray-tracing; diffraction; office; open-spaces

Domaines: Acoustique [physics.class-ph]

Patrick Chevret, Jacques Chatillon. Sound level prediction in open-spaces: implementation of diffraction in RAYPLUS software. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810684⟩