The Topic text calls for research in four particular interlinked areas, and so the ODIN project is naturally aligned with this structure. Each research area forms the focus of a particular technical Work Package, led by one of the four members of the Consortium, with involvement from other partners. These are:

In WP2, Cranfield University (CU) will use their experience in nacelle development to design and conduct RANS CFD investigations of a range of novel compact UHBR nacelles under numerous flight regimes including cruise, high incidence climb, windmill under second segment climb, maximum angle of attack at idle, engine out at cruise and cruise phase windmill diversion, in which all different windmill flight regimes will be for a free windmilling engine scenario. The designed UHBR nacelles will be representative of long-range applications with a mid-cruise Mach number of 0.85. These will generate representative designs for next-generation aircraft that can be used through the other Work Packages, such as the nacelle section rig in WP3. Selected design will be modelling in installed configurations on a representative transonic aircraft at the required off-design conditions. Further, Loughborough University (LU) will analyse and verify these candidate designs using high fidelity, higher-order computational tools. The RANS calculations will then be enhanced and calibrated using results from the higher-order CFD methods and from the nacelle section rig experimental campaign. Finally, the output from all of these activities will be distilled into nacelle design guidelines addressing the whole potential mission envelope.

WP3 is focused on external cowl separation and led by the University of Cambridge (UCAM). Over the past eight years UCAM have been developing a nacelle section test rig in close partnership with Rolls-Royce UK. Five specific nacelle section geometries will be manufactured, as informed by the CU design study, and tested in this heavily instrumented facility. UCAM have a wide variety of advanced experimental methods at their disposal and will be further assisted in this area by the expertise of the Aircraft Research Association (ARA). In parallel, LU will conduct high fidelity simulations of the rig experiment to predict the complex flow physics involved in external cowl separation, including the impacts of transition, which can dominate this flow. These results will all feed back in to the calibration of the RANS calculations in WP2. PART B. I of the Partner(s) Application/Proposal for IA/RIA/CSA (Technical Section) – ODIN 8

The main component of WP4 is a test in the ARA Transonic Wind Tunnel investigating nozzle suppression effects due to the close coupling of the engine and the wing, particularly at off-design conditions. This will feature the ‘AvAUNT rig’ – a unique industrial capability built to accurately simulate and measure independent core and bypass flows of an installed next-generation engine operating at transonic free-stream velocities. This is being developed with the ODIN Topic Manager, Rolls-Royce, in the ongoing AvAUNT Clean Sky 2 project, in response to Topic LPA-01-016. This work will be supported by CU, who will conduct engine cycle modelling, as well as simulating the exhaust suppression effects with RANS for the installed engine case.

Loughborough University will lead the final technical work package, WP5, which tackles the aero-acoustic simulation and testing of an installed novel compact UHBR engine and will address the topic of jet-flap interaction noise – a complex set of noise-producing mechanisms with the potential to become the dominant noise source at lower frequencies. Additionally, this work package will investigate noise levels on the aircraft fuselage in cruise produced by the jet mixing or at higher fan-nozzle pressure ratios by the shock-cell associated broadband jet noise. A wide range of high-fidelity simulations will be conducted using existing and validated time- and scale-resolving acoustic numerical methods such as Large Eddy Simulation (LES) and Detached Eddy Simulation (DES). Far-field acoustics will be assessed by coupling the simulations to the innovative high-order Acoustic Perturbation Equations (APE) solver, currently being developed by LU, to propagate disturbances to the far-field. The current industry standard Ffowcs Williams-Hawkings (FWH) acoustic analogy will be deployed in parallel as a benchmark. These simulations will complement and enhance measurements taken with the AvAUNT rig, which will be upgraded with highly accurate acoustic instrumentation, and ultimately lead to a proposed sensor layout for microphones to be installed on the LPA flying test bed for the evaluation and verification of noise levels.

No less important are the supporting work packages, WP1 & WP6, dealing with ‘Management & reporting’ and ‘Dissemination & exploitation’ respectively. Led by CU and ARA respectively, these will run alongside the technical WPs and ensure that ODIN is running smoothly, to schedule and on budget, and also that all data is being correctly stored and the findings and results of the project are being communicated with the CS2JU and the Topic Manager, and to the wider aviation community.