Planteamiento de un método alternativo, complementario a la normativa existente, para el cálculo de la potencia acústica de una fuente sonora situada en un entorno real

Acoustics and noise control are becoming more and more important. Because of the increasing demand for quietness and acoustic comfort, more attention is being paid to the control of emission of all noise sources. Acoustic models are used to study and control sound levels in a given environment. Acoustic characterization of the noise sources involved is needed to implement these models and the sound power level of these sources is the main parameter. Prior to this thesis, acoustic models of different facilities of the Large Hadron Collider (LHC) were developed by the author at the European Organization for Nuclear Research (CERN). Problems were found in the application of existing standards in real cases. Thereby, the motivation of this thesis was to find a solution to these cases. First, an exhaustive study of the application scope of the different standards that use “in situ” measurements to determine the sound power levels was made. From this study, scenarios frequently found in industrial settings that don’t comply with the necessary requirements given for the standards to obtain the sound power level of a noise source were identified. The aim of this thesis is to complement the existing standards and to propose an alternative method using “in situ” measurements with a sound intensity probe to determine the sound power level of a noise source with “special” measurement conditions. Under these conditions, the standards ISO 3744, ISO 9614-1, ISO 9614-2 and ISO 9614-3 to determine the sound power levels are not adequate. The proposed method offers an alternative in those cases where the sound power level of a noise source needs to be determined but it cannot be stopped or moved, it has the influence of other external noise sources and it has significant acoustic absorption because of the presence of absorbent materials inside of the measurement surface. By using this method, we don’t only determine the sound power level of the noise source under test, but also the absorption coefficient of the absorbent materials inside of the measurement surface and the influence of noise sources external to this surface.