THESE de DOCTORAT - cerfacs

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General Introduction
Contents
1.1 Noise in a combustion chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.2 Scope of the present work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.3 Organization of the manuscript . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Seeing a powerful jet aircraft take off and land, listening to its strong fierce roars when it is
passing by, still inspires awe in many of us. Captured by the magic of flight we usually forget
all the possible annoyances that aviation can produce. For instance, this amazing roar can
quickly become a painful nuisance as there is one departure every 30 seconds in some of the
biggest airports around the world [46]. In our skies, up to 25 millions flights take place each
year and according to ICAO air-traffic forecasts, this number will double by the year 2025 [35].
In terms of ease of mobility this is good news for humanity, however, some problems can be
magnified: consumption of non-renewable energy sources; air pollution; and no less important,
noise. In the last few decades, engineers and scientists have been working together on these
three subjects. Their understanding, prediction and mitigation is crucial.
Noise beyond 75 dB has been proved to be very harmful [58] (see Table 1.1) and particularly
annoying for frequencies between 3000Hz-6000 Hz [104] 1 . According to the International Program
on Chemical Safety (WHO 1994), an adverse effect of noise is defined as a change in the
morphology and physiology of an organism that results in: noise-induced hearing impairment;
interference with speech communication; disturbance of rest and sleep; psychophysiological,
mental-health and performance effects; effects on residential behavior and annoyance; as well
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