Assessment Of Aerodynamic Noise In
An Industrial Ventilation System
Author(s)
A. M. Martins & A. C. Mendes
Abstract
This paper deals with the assessment of aerodynamic noise level generated by an
industrial ventilation system. The system incorporates an axial flow fan
operating with airfoil rotor blades. Measurements were performed using a
modular digital sonometer of high precision, equipped with a microphone and a
frequency analyser. The procedure that was followed enabled us to account for
both the global level and the equivalent frequency level of noise, in the
intermediate range of audible frequencies, using a filter of 1/3 of the octave.
Keywords: aerodynamic noise, axial flow fans, industrial ventilation systems.
1 Introduction
Sound is a form of energy associated with the vibration of material particles in a
medium. The displacements of the oscillating particles are transferred throughout
the matter as acoustic energy, which travels under the form of a sound wave.
Acoustics is the science that studies the generation and transmission of such
sound waves. It concerns not only the phenomenon that occurs in air, which is
audible to humans, but also other phenomena governed by the same basic laws.
Sound may as well be transmitted through solids, liquids and gases. In all cases
we are mainly concerned with the study of a wave motion which is, however,
very distinct from the motion of the individual particles in the medium. Sound is
effectively a mechanical wave motion whose propagation depends on the
physical properties of matter. To be transmitted, sound relies on the elasticity
and inertia of the material in question [1].
Noise, on the other hand, is a sonorous stimulus that is unpleasant to our
hearing and without significant information to its receptor. It can become
nevertheless an issue of primary importance in what refers to human health and
Keywords
aerodynamic noise, axial flow fans, industrial ventilation systems.
Related Book
Other papers in this volume
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