Full Fairing for Main Rotor Head of the RACER demonstrator

Project Information

LATTE

Grant agreement ID: 755483

DOI

10.3030/755483

Project closed

EC signature date 15 May 2017

Start date 1 September 2017

End date 30 June 2023

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 464 437,50

EU contribution

€ 399 543,75

Coordinated by

SIEC BADAWCZA LUKASIEWICZ-INSTYTUT LOTNICTWA
Poland

Periodic Reporting for period 5 - LATTE (Full Fairing for Main Rotor Head of the RACER demonstrator)

Reporting period: 2022-07-01 to 2023-06-30

Summary of the context and overall objectives of the project

The aim of the LATTE project is development in the field of composite parts, what is planned to be realized by designing and manufacturing flightworthy main rotor head fairings for the RACER aircraft.
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 aircrafts that will reach speeds greater than helicopters and that will be able to hover. In the recent years Eurocopter (now Airbus Helicopters) built and tested the X3 compound rotorcraft. Although the X3 has improved the helicopter performance it makes no provision for transport productivity. High fuel consumption, limited payload-range, high noise level and low technology maturity do not allow to enter the commercial market and fill the mobility gap between turboprop and helicopter aircraft. However modern compound rotorcraft like RACER, better than the currently used helicopters, in terms of fuel consumption, impact on environment, cost and performance shall fulfil this expectations. Listed above features are a result of combination of individual components' features of the rotorcraft, like the main rotor fairing, which design and manufacture is the aim of the LATTE Project.
Realisation of the project will include searching for cutting-edge solutions in aviation engineering field, allowing to:
• manufacture innovative Main Rotor Head Fairing of the LifeRCraft demonstrator;
• find the best solution especially in terms of:
- weight of the final product;
- cost of the manufacturing process;
- high shape fidelity with respect to the loft lines provided by the Topic Manager;
- optimization of drag.
Final outcome of the project is delivered rotor hub cowlings that has meet all requirements stated for rotating components. Biggest influence in final design result was fatigue requirements, that fulfillment was challenging, especially in reference to metallic parts and was successfully achieved. Assembly test of all produced component was done to demonstrate geometrical constrains compatibility. Delivery of parts done with all necessary documents to obtain permit to fly by RACER demonstrator.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Work in the first stage of the project was dedicated mainly to design and FEM activities as well as analysis of requirements. The Design activities were preceded by selection of the material for each element, detailed analysis of the Specification and Kinematic Study delivered by the Topic Manager and also analysis of Certification Specifications Requirements (applicable CS29 paragraphs). After delivery of the input data by the Topic Manager, geometry was updated according to made arrangements and first CAD – FEM loop started. Concept Design was discussed during the Preliminary Design Review meeting carried out on 4th of October 2018.

Second stage of the project started after the PDR meeting and it covers detailed definition of the geometry as well as validation of the proposed design. Optimization of the design after PDR was performed. Except changes requested by AH (identified clashes, attachment points, changes resulting from kinematic analysis) also changes of the geometry and materials were done in order to meet the strength requirements and optimize weight. There were several CAD-FEM loops done for the Sleeve Fairing and it’s Support. The structural analyses included static FEM analyses of Hub fairings, attachments and Sleeve.

Activities after PDR also covered preparation of the test campaign programme - the tests are divided to the following groups:
• Material tests
• Mechanical joint tests
• Functional tests of partial air sealing
The material and joint tests were performed within DREAM project dealing with design and realization of equipped engine compartments including cowling for RACER helicopter. This is possible due to using identical materials in both projects. Functional tests of partial air sealing are being currently discussed and will be one of the major steps in the project progress.

Third stage of the project covered further design changes resulting from stress analyses and need of weight reduction. During this stage spherical fairing sealing has been redefined, while the potential sealing materials were tested in order to preselect the best material. Preparation to subassembly test (sealing test reflecting as far as possible real work conditions of the seal) has started - 3D printed test sub-assembly and stand was manufactured in order to verify the kinematics before manufacturing the final test sub-assembly.

Fourth reporting period was dedicated mainly to maturing and finalizing of the sub-systems design and analysis based on the concepts discussed during weekly conferences with AH as well as completion of the test campaign and preparation to parts manufacturing stage. Final design and test campaign of the partial air sealing were succesfully completed.
During 4th RP, the detailed design as well as detailed FEM analysis were prepared. Sub-assembly test of the sealing between the spherical fairings and hub fairings was performed and the test results as well as the test report were accepted by AH. Taking into account results of the CDR, the definition of 2D documentation and final 3D models is in the process of final review. Tooling design process has started. All actions were performed with close cooperation with AH during weakly meetings with design and structural analysis teams.
Final periodic period was focused on production process and finalization of documentation and reports requested for aviation authorities for flight approval of the RACER demonstrator. Several production tools were designed and manufactured to be used for final parts production in order to secure all geometrical and quality requirements. Final quality control done, delivered with produced parts and accepted by AH. In parallel documentation devoted to permit to fly was also finalized and delivered to AH. Final revision was done and acceptance from AH was obtain.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Proposed herein project realisation, will strongly contribute to the established goals and expected impact of the LifeRCraft compound helicopter. Modern material solutions combined with know-how in the field of computer engineering tools, are aimed to led to a low drag and lightweight design. Realisation of the project will allow for cooperation of two research institutes and industry partner allowing for exchange of the experience. Cooperation between Partners and IADP Leader at the stage of the Design Phase already shown different approaches to specific technical problems what allows for finding better than currently used solutions. The Project aims to have also wider impact, exceeding the frame of the Consortium - new technical know-how can be exploited in the future projects and will be disseminated across the industry, especially within the general aviation field - still most of the gliders and ultralight aircrafts are manufactured with use of the wet/ hand layup technique, possibility of introduction of pre-pregs will be an technological breakthrough allowing for manufacturing of improved in terms of weight and structural reliability aircraft parts.

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