Application of metamaterials to reduce environmental noise

The Environmental Acoustics research unit (UMRAE) develops research in order to offer a better control of noise pollution and, to improve the quality of sound environments. Among the UMRAE’s objectives, the development of noise reduction techniques is a concrete response to a strong societal demand. The development of low noise pavements or optimized noise screens, the use of absorbent materials… remain the basis of the proposed solutions, but are still based on « classic » concepts. The improvement of noise reduction systems must now change paradigm to meet the challenges at hand. Thus, the development of innovative solutions based on acoustic metamaterials is an avenue of research to explore. Metamaterials are artificial media whose structure generates specific properties, for example by controlling the propagation of waves in the air. The interest of these materials in the environmental field has been very little developed and few scientific results have been published.

Thus, the objective of the thesis work will be to propose principles of metamaterials-based solutions which could be implemented within the framework of the reduction of the noise annoyance, applied to the reduction of the acoustic emission (action on the source) or to the protection of the inhabitants/passers-by. A specific attention will be paid to reconfigurable metamaterials that can offer very innovative perspectives.

The work will require the realization of a bibliographic study on acoustic metamaterials, the description of the environmental noise problem (and of the standard solutions), and the proposal of possible innovative solutions based on acoustic metamaterials. The student will identify one or more solutions that will be tested, for example by measurements, thanks to the realization of a real scale prototype or at a scale model, and/or by the realization of numerical simulations. These solutions will be compared to conventional noise reduction solutions that are considered as equivalent. Concerning the realization of numerical simulations, it will be necessary to identify the most appropriate numerical methods adapted to the problem (frequency/time methods), in particular among those available within the UMRAE. If necessary, it will require to develop a specific calculation code or to use commercial numerical tools.

The student will have at his disposal the testing facilities and the numerical simulation tools available within the UMRAE laboratory, as well as the expertise in environmental acoustics of Judicaël Picaut (PhD supervisor, UMRAE, Université Gustave Eiffel) and in acoustic metamaterials of Rubén Picó Vila (co-supervisor, Universitat Politècnica de València). Depending on the evolution of the thesis, additional expertise may be sought.