Overview
The EULOSAM project delivered a large-scale half-model to be tested in a pressurised low speed wind tunnel (WT). The model design was performed under a previous CfP topic (JTI-CS-2010-3-SFWA-02-007), while Dassault Aviation delivered a fuselage that has to be modified in order to fit the new laminar wing. The fuselage modifications must be designed in such a way that the fuselage can return to its original shape after the WT test campaign. The model was composed by different parts, therefore, according to the requirements reported in the JTI-CS-2012-02-SFWA-02-029, special care will be dedicated to the surface refinement, to the leading-edge slat waviness and model assembly avoiding step/gap. A control of gap and overlap for the flap and slat under representative loads for each configuration (Take-off & Landing) was performed. In addition, the integration of the pressure instrumentation was performed by minimising the impact on the flow. The model will include:
- A left-hand side modular wing;
- A set of body-wing fairings to fit with the fuselage;
- A left-hand side cross-shaped Horizontal Tail Plane (HTP) that fits with the former model HTP root
- chord;
- A simplified main landing gear and its cavity.
The project will contribute:
- in pushing forward the design of a future jet based on natural laminar flow technology increasing and strengthen the competitiveness of European manufacturing industry;
- to the need to improve the environmental impact of aircraft with regards to emissions.
The project consortium consisted of 3 Small Enterprises who already participated to European projects and have the technical skill and the ability to deliver as result the products before listed according to the JTI-CS-2012-02-SFWA-02-029 requirements. The personnel involved have significant experience in the areas of mechanical wing design, structural verification by FEM and wind tunnel model manufacturing.
Funding
Results
Executive Summary:
The objective of the EULOSAM project was the manufacturing of a large-scale half-model of a business jet for testing in a pressurised low speed wind tunnel. An original model of the fuselage had been provided by the aircraft manufacturer. Its design had been modified for this test in such a way that it can be rebuilt to its original condition for future use in another wind tunnel.
The model to be manufactured is composed of:
- A left-hand side modular wing, including:
- A removable leading edge for different leading-edge concepts
- Spoilers and airbrakes
- Ailerons
- A set of body-wing fairings to fit with the fuselage.
- Adaptations to the left-hand side cross-shaped horizontal tail plane that fits with the former root chord of the tail model.
- A simplified main landing gear and its cavity.
- An adaptor for mounting the model onto the wind tunnel balance.
The wing was an innovative low-sweep high aspect ratio design with an aerofoil conceived to be laminar in cruise conditions (M = 0.75 at 43 kft). Innovative high-lift systems are outputs from former studies and include Krueger slats and innovative flap devices.
The design and the manufacturing of the model presented some challenging aspects:
- Due to the high aerodynamic loads in the pressurised wind tunnel, the usual wing-"box" must be replaced by a massive and solid steel billet. Hundreds of very long channels must be drilled to install the tubes that conduct the local pressures at the wing surface to the scanivalve pressure sensor.
- Expensive steel qualities must be used for all model parts in order to cope with the high stresses induced by the high loads.
- Due to the wind tunnel pressurisation, the Reynolds number is high and, consequently, the boundary layer much thinner than it would be if the wind tunnel were not pressurised. Therefore, in order to prevent premature boundary layer transition, a very smooth surface must be realised, and only very small tolerances are acceptable for gaps and steps between assembled parts of the model.
Major difficulties were experienced during the manufacturing of the different parts, due to the deficiency of one of the parties in charge of it. The partial transfer of these activities to a new party allowed to partially recover the situation and to deliver the most critical elements as per listed in the results. This has allowed the project to continue beyond the horizon of Clean Sky in order to meet the initial objectives.
The results presented in this document about the EULOSAM project are then limited to activities actually completed by end of December 2016.