Determination of in-duct fan sound power levels (6th International Congress on Sound and Vibration, Lyngby, July 1999)

Résumé et principaux résultats

This paper presents results of an experimental programme carried out before the last revision of ISO 5136 standard concerning in-duct fan noise measurement, in order to bring additional information for this revision. The in-duct outlet sound power levels of a 630 mm axial flow fan are measured using different microphone shields (slit tube, foam ball and nose cone) and are compared with those measured in free field outside the duct. The duct is fitted on its outlet side with a big unlined exponential horn to allow most of the in-duct sound energy to escape to the outside. Furthermore this horn behaves as an anechoic termination necessary to perform in-duct measurements.
The influence of a star flow straightener as the one specified in ISO 5801 (fan performance measurement) is also examined.
This information has been proved useful for the revision of ISO 5136.

Thème

Ventilateurs

Mots-clés

Acoustique, Ventilateurs

Auteurs

GUEDEL Alain