The research methodology, illustrated in Figure 1, proceeds along a low-to-medium TRL approach: innovative technologies and methods are first investigated in detail on laboratory-scale simplified configurations, then modelled and validated through theoretical-experimental-numerical correlation, and eventually deployed to industrial prototypes. Finally, the potential of application and transfer of technology towards various sectors of activity is assessed.
WP1 aims at mitigating noise emissions in the most straightforward and effective way: by reducing the noise generation at the source. In a very large majority of industrial applications, aerodynamic noise results from the interaction of unsteady flows with solid surfaces. Innovative techniques will be investigated here, aimed at reducing the strength of turbulence-surface interactions through porous and/or compliant materials, passive flow control approaches (serrations and vortex generators) and advanced morphological optimization techniques.
WP2 implements the second step of our comprehensive noise mitigation plan. After reducing the noise production in WP1, the objective of WP2 is the attenuation of the sound after its generation, by means of sound absorbing liners incorporating novel materials. New concepts have emerged such as multiple-degrees-of-freedom (MDOF) liners, heterogeneous metamaterials and anisotropic micro-perforates. These innovative concepts exhibit interesting properties, demonstrated from theoretical analysis or small-scale laboratory experiments, but their potential remains to be understood.
WP3 completes the efforts of WP1 and WP2 for the cases where noise isn’t only an exterior radiation issue (such as in wind turbines or aircraft high-lift devices), but is also affecting the acoustic comfort of passengers through structural transmission mechanisms. Interior cabin noise is indeed a pressing issue in the automotive, railway and aircraft industries, often strongly related to shape optimization, and new concepts have emerged in that field as well.
In WP4, laboratory-scale experiments will be put in place, involving an unprecedented combination of experimental diagnostics. In this WP, the configurations will have to be geometrically simple enough to permit such a combination of diagnostics, while representative of the physical mechanisms at stake in the full-scale industrial configurations. For the sake of time- and cost-efficiency, one important objective of WP4 will be to devise validation benchmarks permitting to test multiple technological innovations. This will also have the merit of permitting a fair comparison between different solutions.
In WP5, the configurations of interest are full-scale industrial prototypes or demonstrators, put at disposal of the ESRs by the industrial Beneficiaries and Partners of the project. The components will still be investigated in a laboratory environment permitting detailed measurements and concept validation, but include all the complexity found in the full-scale devices, in terms of non-dimensional numbers (Re, M, Sr, He), multiple-component interactions, integration aspects, etc.
WP6 will gather the outcomes of all previous WPs in the form of synthesis reports, comparing the relative performances of the various technologies investigated for each problem, in terms of classical engineering metrics, but also in the form of psycho-acoustic indicators. Cross-sectorial workshops will be planned where the ESRs will have the opportunity to explore the transversal potential of their respective methods for each sector of activity represented in this network and beyond.
WP7 ensures the good coordination of the management, scientific and training activities. The applicants acknowledge that this consortium is rather large compared to the standards of European Training Networks, being for the sake of the variety of technologies, scientific disciplines and sectors of activity to which the ESRs will be exposed. It does therefore require an efficient management of the research, trainings, and secondments of the fellows.
Finally, WP8 implements all required measures for an efficient dissemination of the research outcomes, exposure to general public through outreach actions, and defines a Data Management Plan in line with the Open Science initiative.