– Amazingly Better Acoustics
HAMBURG, Germany, April 2011 /PRNewswire/ — Aircraft noise is one of the biggest environmental concerns. But in the interior of aircrafts, passengers and the crew also have to be relieved from noise emissions. At the Expo 2011, the Pelzer Consult GmbH presented its worldwide novel aircraft trim panel that reduces the noise level in the interior by up to 10 decibels.
The supplier of VIP aircrafts will be excited about it: Thanks to the high reduction of the noise level, the interior noise and speech intelligibility has been appreciably improved. However, due to stricter health guidelines, the new trim panels are also suitable for personnel rest rooms or the First Class areas in commercial aircrafts.
In order to measure all important acoustic parameters, an acoustic test bench was especially developed which was used to acoustically measure whole exterior aircraft walls in every detail including interior trim panels. The evaluation resulted in the concept of a novel aircraft trim panel, which leaves behind substantially less noise energy.
Conventional trim panels use sandwich panels with closed covering layers, which are a big acoustic drawback. Closed honeycomb sandwich panels will result in an undesired loudspeaker effect: The rigid honeycombs link up those covering layers prompting vibrations and radiating disruptive airborne noise. “It is a paradox. The conventional closed sandwich panels make for ideal flat loudspeaker diaphragms!”, says Hans-Peter Keller, the Research and Development manager of the Swiss Pelzer Consult. “We got rid of the loudspeaker effect. For our panels, we use acoustically open covering layers. This allows the sound to pass and to be better absorbed. An additional decoupled sealing film will prevent, by the way, that airborne noise will make it through our open honeycombs from the outer wall of the aircraft into the interior. With the weight being the same, the acoustics is amazingly better.”
It is the first time that thermoplastic, 100% recyclable 3-D supporting material has been used requiring only a fraction of the production time.
Aircraft Composites Consortium – a merger of the Swiss companies Plastika Balumag AG and Pelzer Consult GmbH as well as the German Tubus Bauer GmbH – is the only platform in the world that is able to mass produce the trim panel for which a patent application has been filed.
