CREDO is a Specific Targeted Research or innovation Project (STREP) within the 6th European Framework Programme, Priority 4: Aeronautics and Space.
Motivated by the aircraft industry’s acute need to validate and calibrate prediction models and advanced design tools for the cost-effective design of low-noise cabins, the CREDO project addresses a critical deficiency in the available data by developing technologically viable experimental procedures and analytical tools by which the sound power entering an aircraft cabin can be determined sufficiently quickly, accurately and with the necessary spatial resolution. Owing to the reverberant nature of the sound field in an aircraft cabin, existing methods are categorically insufficient for this task and entirely new methods shall be developed.
Two parallel approaches are pursued. In the first, the sound power entering the cabin is locally extracted from local measurements of the total field. This approach employs a hitherto unavailable microphone array concept: the double layer array, together with purpose-developed processing and procedural algorithms. In the second approach, the sound power entering the cabin is determined globally through numerical inversion of measurements throughout the entire cabin using the new experimental tools. This will be achieved with pioneering Inverse Finite Element implementations and groundbreaking Inverse Simplified Energy Methods, developed in close connection with novel measurement technology and algorithms, extended from the local to the global level. At all stages in the project, the interaction between local and global approaches and between measurement and processing is exploited to maximum innovative effect.
The successful implementation of the results of these developments is ensured by a carefully designed validation campaign involving ground and flight tests in both aircraft and helicopter cabins.