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Design and Realization of equipped engine compartments including cowling for a fast compound rotorcraft

Periodic Reporting for period 4 - DREAM (Design and Realization of equipped engine compartments including cowling for a fast compound rotorcraft)

Reporting period: 2021-01-01 to 2021-12-31

The aim of the DREAM project was to develop and manufacture the main elements constituting the engine compartments of the High Speed Rotorcraft (Cowlings, Air Intake, Engine Bay Ventilation).

Development in the field of rotorcraft and parallel improvement of a fixed-wing aircrafts, resulted in new concepts, that were designed to combine airplane and rotorcraft capabilities, giving birth to a VTOL aircraft that will reach speeds greater than helicopters and that will be able to hover. Creation of different concepts and prototypes speeded up in 40's, since that time many projects were initiated, however most of them ended up on the prototype phase. The latest achievements in this field belong to Sikorsky and Eurocopter (now Airbus Helicopters) companies. Eurocopter in the recent years successfully built and tested the X3 compound rotorcraft (first compound rotorcraft built in Europe since the 1950', when the Fairey Rotodyne was flown).

RACER demonstrator will help to improve industrial and scientific capabilities in the field of compound rotorcrafts giving Europe opportunity to stay on a predominant position in the rotorcraft industry across the globe. It is worth to emphasize, that within completion of the RACER project, not only industrial but also societal and environmental aspects shall be taken into account. Continuously increasing number of flights and predicted further growth of air travel, results in increased impact on environment and is a challenge facing aviation industry in terms of finding new and more environmentally-friendly solutions that can enter into service in a relatively short period of time, taking into account dynamic (observed and predicted) congestion increase in the airspace. The above is confirmed by the Clean Sky 2 Factsheet: "Air transport contributes today about 3% to global greenhouse gas emissions, with traffic expected to triple by 2050. Although other sectors are more polluting (electricity and heating produces 32% of greenhouse gases), this expected growth makes it necessary to address aviation’s environmental impact. Meeting the EU’s climate and energy objectives will require a drastic reduction of the sector’s environmental impact by reducing its emissions. Maximising fuel efficiency, using less to go farther, is also a key cost-cutting factor in a very competitive industry – and as air traffic increases, better noise reduction technologies are needed.". Moreover increasing expectations in terms of door-to-door mobility underlines the need of searching for more affordable and better performance solutions.

Realisation of the DREAM project included searching for cutting-edge solutions in aviation engineering field, allowing to:
• manufacture innovative engine compartments of the Compound Rotorcraft demonstrator
• find the best solution especially in terms of weight, costs and shape fidelity of the parts.

The final parts were manufactured almost entirely of composite materials, including parts of the engine bay and those exposed to high temperatures thanks to use of high temperature composite materials. All the parts were designed with the aim to meet certification requirements and to be maintenance-friendly: the applied solutions were often reconsidered in order to assure easy access to interior of the cowlings as well to assure fast assembly/ disassembly.
First stage of the Project was dedicated to Concept Design Definition and has been covered by CAD and FEM activites (input was delivered by the Topic Manager). Tasks within this part of work were focused on general and detailed geometry development, FEM analysis, material and manufacturing process definition of Upper Cowlings, Air Intake and Ventilation Ducts for the RACER Demonstrator. It resulted with a documentation including set of detailed 3D Catia models for every System and reports from Finite Element Method Analyses. During this reporting period also series of screening tests were performed, which resulted in the choice of composite material for parts manufacturing.

Second stage of the project was focused on definition of the detailed design, which covered detailed FEM analyses as well as detailed geometry definition taking mainly into account FEM-CAD loops and Topic Manager’s requirements. First draft of the whole 2D documentation has been defined. Detailed discussions with the potential sealing manufacturers took place, official search for metallic parts manufacturers has started. Test campaign has been completed (only additional tests of a new material were being carried out). First mould (and the most complicated multi-piece mould used in the Project) has been manufactured – the mould served for manufacturing of the first parts (dedicated to Ventilation tests). Process of manufacturing and assembly drawings fine-tuning has started. Exhaust, Lower MGB and Centre Engine Cowling toolings’ design was completed – preparation to the tooling manufacturing has started. A number of Dissemination and Communication activities was completed.

Within 3rd Reporting Period Test Campaign (including additional tests of high temperature composite material) and FEM analyses were finished, while their results (reports) delivered to and accepted by the Topic Manager. 3D design documentation was frozen and most of 2D manufacturing drawings were released after they were fine-tuned. Subcontractors for manufacturing of the sealings and metallic parts were selected. Tooling for the sealings and the sealings were manufactured by the subcontractor. LA composite started the tooling and parts manufacturing process – Exhaust Cowlings (including high temperature resistant parts) and Centre Engine Cowlings were manufactured.

The last part of the Project was dedicated to remaining moulds and parts manufacturing and completion of the Permit to Fly documentation. The parts were divided into two batches: Cowlings (shipped first to the Topic Manager's premises) and Air Intakes with Main Gear Box Cowlings shipped as a second batch. The manufacturing schedule was arranged taking into account assembly order and RACER schedule.
Results of the project were disseminated/ communicated along its duration through information on web-sites, during conferences and by publication of scientific articles. Lessons learned during the Project were further taken into account by eachbPartner of the Consortium allowing for more efficient realisation of the Projects, including EU granted projects. Results obtained were further exploited, giving basis for more methodical approach to design processes, while manufacturing activities brought validation of complex multi-piece mould manufacturing process.
Proposed project realisation contributed to the established goals and expected impact of the RACER demonstrator. The project improved innovation capacity and knowledge integration.
Thanks to the DREAM Project strengthening of cooperation between research and manufacturing centres in Poland and Czech Republic was possible, what could be seen by different projects carried out together on public and commercial basis, giving potential to strengthen European competitiveness of the general aviation sector.
Technical cooperation resulted also in design processes improvements and new technologies introduction through transfer of know-how, experience and guidelines between Partners.
RACER Airbus Helicopters
RACER Airbus Helicopters