DLR refines aircraft cabin noise

Deutsches Zentrum für Luft- und Raumfahrt (DLR) is Germany’s national research centre for aeronautics and space. Their Experimental Methods department set out to investigate noise transmission and propagation on the Airbus A320 family of aircraft. Brüel & Kjær’s multi-field microphone measured the uncertain sound field inside the aircraft cabin, and between the fuselage and the lining.

Challenge

Investigate noise transmission and propagation on the Airbus A320 family of commercial aircraft, while improving the methodology of flight tests.

Solution

Relating external vibration and pressure to interior noise, using multi-field microphones to measure the uncertain sound field inside the aircraft cabin, and in the small areas between the fuselage and lining.

Results

By combining sound measurement results with those from pressure sensors and accelerometers, the tests established a clear link between coherent fluctuations in the turbulent boundary layer and the noise experienced in the cabin. This enabled Airbus to adapt the fuselage to avoid these fluctuations.