“Noise is a highly sensitive topic,” explained Henning Scheel, co-leader of research at the acoustic lab. “Some noises are easy to ignore, even at high volumes. Others are deeply annoying.”
The ZAL’s 8.5-metre-long fuselage demonstrator can be subjected to sound waves around its full circumference via a system of 128 individually controllable speakers. This setup was designed to replicate engine noise from existing and future propulsion concepts.
“The acoustic lab accurately reproduces conditions that apply in flight,” Scheel said. “This allows us to examine new noise reduction measures in the cabin, rendering expensive test flights unnecessary. The acoustic chamber also offers us the opportunity to perform detailed comparisons between simulation models and real-world physics.”
With the expertise gained at the ZAL acoustic lab, Airbus’ interior noise teams are pinpointing where noise enters the cabin and how it is spread and transmitted. They then can explore how background noise can be reduced – for example, by making minor structural modifications, using different types of insulation, or applying new materials such as embedded vibration dampers that absorb noise in a specific frequency range.
“We will significantly shorten the development cycle for new solutions with the help of this demonstrator,” added Martin Wandel, who co-leads the research with Scheel.
The ZAL chamber can accommodate fuselage demonstrators of up to 8m high and 15m long, including for Airbus’ A350 XWB and A330 widebody aeroplanes. The initial fuselage mock-up will be thoroughly investigated before work begins on representative cabin interior components. Tests with passengers are also planned for the future.
The acoustic lab is part of a newly-created infrastructure at the ZAL, which opened earlier this year as the technological research and development network for the Hamburg metropolitan region’s civil aviation industry. The ZAL functions as an interface between the aviation sector, academic and research institutions, and the City of Hamburg – with Airbus Operations being one of the three largest shareholders.