Methodology and Work Packages
The WP1 organizes the implementation of a management structure including an Advisory Board (in which Airbus has readily accepted to participate with two research groups, together with the DNW, GKN Aerospace and Griff Aviation), the coordination of the scientific activities, the collection of reports, communication with the EC, the organization of meetings, setting up a web site including intranet and extranet sections, networking with other EC and national projects, risk management, the elaboration of a Consortium Agreement and enforcing IPR rules, and the coordination of the dissemination and communication activities.
The WP2 supports the experimental and numerical activities through specific developments. High-sensitivity and high-resolution beamforming techniques for the identification of the dominant sources and quantitative assessment of advanced noise mitigation techniques will be upgraded in Task 2.1. Advanced data processing methods, necessary due to the vast amount of data that will be generated by the project, will be developed in Task 2.2. Simulation techniques will be further developed too: low-order and semi-analytical methods, also in a view to be able to reproduce the perceptive features of the recorded sound field (Task 2.3), high-fidelity CAA methods (Task 2.4), optimization methods (Task 2.5), propulsive efficiency and gaseous emissions models (Task 2.6), and the modelling of flow/acoustic control such as advanced porous liners (Task 2.7) or leading/trailing edge serrations (Task 2.8).
The backbone of the project is then constituted by WPs 3 to 7 as follows. In WP3, the consortium will explore, by means of dedicated experiments, the aerodynamic performance and aeroacoustic issues associated with wall-mounted and buried propulsion systems (configuration A, Task 3.1), pylon- and control surface-mounted distributed propulsion systems (configuration B, Task 3.2) and multi-rotor systems (configuration C, Task 3.3). The design and manufacturing of the configurations will be mutualized in order to save costs: the configuration A of will be installed and investigated in the laboratories of UBRI and UTWE and the configuration B will be shared between the laboratories of ECL, TUD and NLR. The configuration C, involving much lower costs, will be studied in the VKI lab only. The collected databases are meant to provide a new insight into the physical mechanisms and permit the validation of the methods developed in WP4, they will guide the development of optimization strategies in WP5, and suggest the most promising noise mitigation strategies to be tested in WP6. A broad design space will be scanned by having a motorized propulsor-airframe positioning system.
Based on the outcomes of the experimental campaigns, selected configurations will be simulated using methods ranging from low-cost (e.g. semi-analytical) to high-fidelity (LES) in WP4. The low-cost techniques will be further improved and validated to allow their inclusion in optimization platforms in WP5. The LES datasets will permit an in-depth analysis of the physics involved in aerodynamic and acoustic installation effects, and support the fine-tuning of the low-cost models.
In WP5, multi-disciplinary and multi-objective optimizations will be carried out to obtain the best trade-off between noise production and shielding effects, propulsive efficiency and derived metrics such as fuel consumption or gaseous emissions. The results will first demonstrate the capability of the numerical models to predict accurately various antagonistic effects of flow distortion, acoustic scattering, etc. In the second step, the problem constraints will be relaxed to explore a wider parameter space than in the experiments and potentially further increase the gains.
Dedicated mitigation strategies will be devised in WP6. Advanced liner concepts developed for the treatment of aeroengine nacelles can be distributed over airframe portions subjected to the maximum incident acoustic radiation. Porous materials and serrations show promising potential for the mitigation turbulence-airfoil interaction noise in pylon-mounted DEP systems. Rotor control can yield tonal noise reductions. The mitigation strategies will be implemented in selected simulation platforms developed in WP4 and selected test mock-ups of WP3 for cross-validation. Finally, the loop will be closed by running the optimizer again, including this time the effect of the mitigation strategies.
The WP7 will ensure the physical relevance of the research through a preliminary non-dimensional analysis, and evaluate a posteriori the scalability of the research outcomes, including the simulation and optimization tools and the noise mitigation technologies, to full-scale novel aircraft architectures.
Finally, the WP8 encompasses the collection, documentation, archival and publicity (through the open-access CERN-hosted ZENODO repository) of the databases generated in WPs 3-6 (Task 8.1), the provision of guidelines for the quiet and efficient implementation of integrated airframe-propulsion systems, with recommendations about the potential of noise flow/acoustic control technologies to maximize the benefits of installation effects (Task 8.2), and rating the achieved TRL level of the different concepts and technologies towards the horizon 2050 objectives with an updated roadmap (Task 8.3).