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1. Notions of airborne acoustics
Sound waves are not transmitted in a vacuum. They need a material support to propagate. In this first part, we'll look at the propagation of waves in the air around us.
The quantities we're about to consider, whether pressure fluctuations or particle displacements, are oscillatory quantities; their value varies over time around a mean level, which is unimportant, and which is ordinarily, and by convention, considered to be equal to zero.
1.1 Periodic acoustic wave
The noise perceived by the ear is linked to the variation over time of the pressure p. The simplest form corresponds to a sinusoidal evolution of p. In this case, the phenomenon can be characterized by just 2 quantities, e.g. the...
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Notions of airborne acoustics
Noise in liquid or solid media
Bibliography
Circuit calculation codes
Pressure fluctuations emitted by a pump (or valve) must be analyzed to determine the risk they represent for the circuit (stresses, vibration levels, natural frequencies, forces exerted on the structure).
As we have already seen
Standardization
All aspects of testing standards are covered in depth in the reference . We have extracted the most important passages:
Airborne noise measurement
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