ASTRAL

Noise emissions from commercial air transport is a crucial issue in relation to public health, economic competitiveness and technological developments. For instance, the Strategy Research and Innovation Agenda, recently released by the Advisory Council for Aeronautical Research in Europe, has defined the vision for the reduction of aviation noise in 2050 in Europe. This sets out a number of ambitious targets for the reduction of noise and air pollution, including a 65% reduction of perceived noise levels by 2050 compared to the year 2000. At the national level, the Conseil pour la Recherche Aéronautique Civile has defined similar targets. The present project aims to develop novel acoustic treatments to significantly reduce noise emissions from aircraft. This is a collaborative effort between the SAFRAN Group and the Laboratoire d’Acoustique de l’Université du Mans (LAUM). Their combined expertise in fundamental research and technology innovation in acoustics will enable the development of novel acoustic treatments that can be efficiently integrated onto future engine architectures. A number of research directions will be considered in this project. * The interactions between the acoustic treatment, the sound field and the air flow. In particular the impact of a perforate liner on aerodynamic losses will be investigated. * Novel experimental techniques will be developed to assess the performance of acoustic treatments with flow, high sound levels and complex sound fields. * Models will be developed to predict the effects of non-linear sound propagation and swirling flows on liner performance. * New liner technologies will be developed, including porous material, metamaterials and active noise control. In addition to these research and development activities, the project will also contribute to technology transfer, training events and dissemination.