The Project LIGHT-COWLS aimed to find out a way to produce rotating nacelle components for aircraft engines by using composites materials with high Tg, production method can be RTM or ATL. In particular the design and manufacturing of rotating nacelle of the CROR was targeted. The materials to be used for this development were high Tg resins and fibers as reinforcement. Thus, the project looked for a cost-effective way of producing conical cylindrical components of about 1,5 m. diameter in these composites material. The project included the design and fabrication of a component for a demo engine SAGE2. The aim was to get a cost-effective way of manufacturing, complex shape parts for aeroengines.
The aircraft manufacturers needed to find higher engine efficiency with much lower fuel consumptions. For this target, several developments have been launched by engine manufacturers.
One of the most amazing engines from the architecture point of view is the so called the Contra Rotating Open Rotor. This engine is to be proven to save 30% fuel consumption over successful engines such as CFM56. To prove this the SAGE 2 in CLEANSKY is the Integrated Technology Demonstrator initiative in which a full engine was developed to carry out a Ground test managed by the CS engine leader’s companies.
A Consortium of three organisations from two from Spain and from The Netherland, was formed to develop from the preliminary design up to the delivery of rotating nacelle (cowls) to the SAGE 2 Open Rotor Demo Engine.
These components are in the forward area below the fwd. fan blades, as well as in the central area on top of the counter rotating area and finally as well below the aft fan blades. in a highly vibrational environment and high thermally stressed as well. The weight constraint is a capital requirement to meet the full weight goal of the engine so for this the rotating cowls has been designed and manufactured in composite. The main constraints and the multitude of interfaces has made the LIGHT-COWLS project of a high complexity R&T.
The LIGHT-COWLS project, led by EURECAT (former ASCAMM) and with partners Amade and Airborne had to consider the following main components functions, for rotating cowls:
- To avoid loss of pressure from the internal cavities
- To provide outer propulsor aerodynamic shape
- To duct the cooling air flow into rotating nacelle internal cavities
- To protect Pitch Change Mechanism (PCM)
- To provide access to PCM for maintenance
- To resist environmental conditions
- To ensure airplane safety
- To fit an adapt to the propulsion
- To meet requirements
The steps of the project can be summarised as:
- Analysis of requirements
- Selection of architecture for the cowls
- Material and process detailed selection
- Risk analysis continuous monitoring
- Selection and analysis of concept for the Concepts
- Performing all preliminary design phase
- Carry out material characterization
- Carrying out manufacturing trials
- Passing the Preliminary Design Review (PDR)
- Carry out Critical Design Phase
- Pass CDR
- Perform manufacturing, control and delivery of all cowl parts to SAGE 2 OPEN ROTOR Demo Engine.
With this approach the project was fully achieved, the marked objectives and all components are assembled in the demo engine.