Engineering news
British aerospace company Reaction Engines has signed a €10m European Space Agency (ESA) contract which will enable the development of a ground based demonstrator of its new class of aerospace engine.
Reaction Engines synergetic air-breathing rocket engine (Sabre) could allow an aircraft to travel directly into Earth orbit. The technological breakthrough has come with the development and testing of the engine’s pre-cooler, which is designed to cool continuously the incoming airstream from more than 1,000ºC to –150ºC in less than 1/100th second.
The hope is that Sabre will lead to the development of the Skylon single-stage-to-orbit reusable launcher, bringing cheaper and more reliable access to space.
The signing of the contract with ESA represents the final piece of the British government’s £60 million commitment of grant funding towards the Sabre programme.
In November 2015, BAE Systems invested £20.6 million in Reaction Engines to acquire 20% of its share capital and agreed to provide industrial, technology development and project management expertise to support Reaction Engines during its development phase.
The agreements now in place between Reaction Engines, ESA and the UK Space Agency (UKSA), together with the working partnership with BAE Systems, set the framework for Reaction Engines to deliver the world’s first sabre ground demonstrator engine by the end of the decade.
Mark Thomas, chief executive of Reaction Engines, said that the funding was a “further vote of confidence not only in the revolutionary potential of this technology” but in the company’s ability to deliver the Sabre engine.
The Sabre engine will operate as a jet engine and rocket. Its air-breathing characteristics from take-off to Mach 5 mean Skylon will be able to reduce the amount of heavy liquid oxygen carried. That would cut the weight of the vehicle, dramatically lowering fuel consumption. The weight reduction would enable Skylon to be designed as a conventional, reusable aircraft.
At the heart of the breakthrough is the development of the pre-cooler, made from inconel 718, a strong and highly corrosion-resistant aerospace alloy.
The heat exchanger tubes are arranged in involute spirals, and formed in larger modules to make a cylindrical drum. The coolant is introduced on the inside of the drum and then spirals its way to the outside in a counter-flow thermodynamic motion.
The hot air, meanwhile, moves in the opposite direction to the cold helium in a cross-flow motion, flowing over the tubes rather than along their length. That increases the heat transfer because it causes a lot of mixing in the wakes around the tubes.
Franco Ongaro, director of technical and quality management, at ESA said: "Reaction Engines and ESA have been working together since 2008 to make the Sabre concept a reality. This new contract marks an important milestone in our continued collaboration to mature the Sabre engine design. It should take us to a point where we can expect to be testing a demonstrator engine in 2020.”