Air passengers to enjoy silent aircraft cabin

Hamburg, June 6: Scientists at the German Aerospace Centre in Braunschweig are currently testing material that can make an aircraft cabin far quieter.

Until now, airplane designers and aviation scientists have largely devoted their efforts to reducing engine noise rather than attending to sounds inside the cabin.

A project called CoSiCab (comfortable silent cabin) under the Deutschen Zentrums fur Luft- und Raumfahrt (DLR) is concerned with noise reduction using adaptive system technology, or adaptronics.

Its objective is to measure, simulate and reduce noise inside an aircraft.

The main sources of noise are hydraulic systems, airconditioning, the engines and air flow along the fuselage. As the air moves, it sets the metallic structure of fuselage vibrating. And the noise created is transferred to the cabin.

This is the problem adaptronics will address by using smart and multifunctional materials like piezoceramic fibres and film.

With its many openings, doors and hatches, the fuselage is a complex structure and generally considered to the most critical sub-assembly of an aircraft.

Whereas aluminium alloy has always been the material used to build fuselages until now, companies like Boeing and Airbus are increasingly turning to carbon-fibre-reinforced plastics (CFRP) which are lighter, harder and stiffer than metal.

But CFRP vibrates more easily than metal. This is where adaptive system technology comes into the picture since smart materials it employs can sustainably damper vibrations.

UNI