Aircraft

The contra-rotating main turbine of a proposed precooled engine called Scimitar is to be tested next year, as part of the €7 million ($10 million) European Union-funded hypersonic transport aircraft project Long Term Advanced Propulsion Concepts and Technologies (Lapcat).

According to Scimitar’s developer, Oxfordshire, UK-based Reaction Engines, the engine uses cryogenic liquid hydrogen to precool the air entering its turbo-compressor to provide high- pressure air to its combustion chamber, and is capable of sustained Mach 5 flight. It would power Reaction Engine’s M5 vehicle design, the A2.

The A2 is a civil transport aircraft carrying 300 passengers to meet the seat-mile economics deemed necessary for competitive services. The company will its cryogenic facilities at its B9 test stand to generate the mass flow needed to run the Scimitar’s contra-rotating main turbine.

Reaction Engines managing director Alan Bond says: “The overall project is going well and we will go into a second study in about a years time, when we have some significant propulsion work.”

In future the Rolls-Royce Viper could also be used to provide the mass flow to test the company’s heat exchanger concept. Reaction Engines claims Scimitar also has a second, turbine-operating mode that provides bypass airflow to allow efficient subsonic flight and moderate take-off noise.

In Lapcat the A2’s competitor is German aerospace centre DLR’s Mach 8 vehicle, which uses a rocket-based combined-cycle engine.

Lapcat ends in April 2008, but the EU is to fund a €10 million follow-on project called Lapcat II.This will investigate the DLR and Reaction Engines concepts in more detail.