AIRCRAFT CABIN NOISE AND VIBRATION PREDICTION AND ACTIVE CONTROL

• The active control of noise and vibration in passenger aircraft cabins generally rely on adaptive multi channel feedforward control of disturbing acoustic cabin modes based on a set of control sources and error sensors with optimized locations, or on feedback control in active headsets or in quiet seats. The structural aircraft fuselage vibrations produced by the propulsion system and turbulence pressure fluctuations acting on the external fuselage generally excite the interior cabin sound field. Cabin noise in turboprop aircraft and jet aircraft with tail-mounted engines are usually dominated by tonal noise related to the fundamental blade passage frequency and the jet engine spool imbalance frequencies respectively. The jet noise -engine exhaust noise- and turbulent boundary layer noise, on the other hand, have broadband characteristics. The active control of tonal noise in aircraft is of global character and involves multi channel active noise control or multi channel active structural acoustic control. The locations of the secondary sources and error sensors are optimized for the acoustic noise attenuation over a range of flight conditions and are selected from a set of potential configurations. Generally, the active control systems for reducing the tonal cabin noise are based on variants of the multi channel Filtered-X LMS algorithm, and both time domain and frequency domain algorithms are used. Feedback control in active headsets or in silent seats addresses the broadband cabin noise.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Signalbehandling (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Signal Processing (hsv//eng)

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