Periodic Reporting for period 3 - ALFA (Advanced Laminar Flow tAilplane)
Berichtszeitraum: 2019-09-01 bis 2020-10-31
The reduction of the aerodynamic drag of the aircraft by application of NLF on the Horizontal Tail-Plane of a typical business jet will offer a potential of 1% decrease of fuel burn thereby reducing the environmental impact of the expected growth of aviation travel.
The main project objectives of the ALFA project are:
1) To develop, design and manufacture a full-scale NLF HTP (Natural Laminar Flow Horizontal Tail-Plane) Demonstrator
2) To push forward the maturity-level of NLF technology towards market introduction on business jets
This has accumulated in a trade-off phase were the design solutions were evaluated in terms of NLF feasibility and cost, weight and maintainability aspects. The outcome of the trade-off phase was a selection of the technologies to be included on the Demonstrator.
The main features of the technologies focussed on were:
1) Optimized assembly processes to minimize the tolerances.
2) Two innovative manufacturing technologies for the leading edge, based on RTM technology (single sided tool) and autoclave technology, with different, promising multi-criteria evaluations, while both technologies have the potential to achieve the laminar criteria.
3) Automated masking operation for fastener heads.
A detailed Demonstrator lay-out has been generated and a detailed design phase has been initiated to further converge towards part-release. In parallel, mono-tool and assembly tool conceptual design has been started.
1) Application of an approximate 50 [um] thick anti-abrasion Ni-coating on a curved composite Leading Edge by means of a chemical/electrical deposition process complying to NLF requirements in terms of stringent surface quality.
2) Control of Leading Edge interface to Torsion-Box in order to be compliant to the stringent NLF step and gap requirements.
3) Production of an Hi-Tape UD composite Leading Edge using an automated fiber placement process applying dry fibers to a male mould.
4) Introducing integrally stiffened thermoplastic material on primary aircraft structure (Horizontal Stabilizer Torsion-Box Skins).
The successfulness of the above pursued technologies can only be sufficiently evaluated at the end of the project. In case of full success, and competiveness against non-NLF HTP designs, a NLF-zone on the upper and lower skins up to 50% of the cord can be expected.
The expected level of NLF would reduce the fuel burn of a typical business-jet with 1% and could be considered as a noticeable contribution in reducing the environmental impact of the foreseen growth of global aviation.
The expected results until the end of the project will be a manufactured HTP Demonstrator allowing an assessment of the capacity to manufacture such structure at an affordable price. This will open the door to an exploitation of ALFA results in a future aircraft program, thereby increasing the competitiveness of Europe’s business jet manufacturers and suppliers.