Reaction's Sabre engine 'precooler' cools 1,000ºC air in the blink of an eye

Air hotter than 1,000ºC has been cooled in less than 1/20th of a second by a vital ‘precooler’ for the potentially revolutionary Sabre spaceplane engine.

The test at airflow temperature conditions representing Mach 5 mark a significant milestone in the development of the air-breathing rocket engine, which is designed for hypersonic atmospheric flight up to that speed – more than twice as fast as Concorde – and space travel at more than Mach 20.

The demonstration by developer Reaction Engines showed the precooler’s ability to successfully cool airflow at speeds significantly faster than the operational limit of any jet engine-powered aircraft in history.

Reaction Engines previously told Professional Engineering that the precooler has thousands of thin-walled tubes filled with helium, rapidly absorbing heat thanks to its high surface area with low weight. Methanol will be injected to prevent water vapour from solidifying in the freezing temperatures that result.

“Our heat exchanger technology has the potential to revolutionise what can be achieved with thermal management across a range of industries, from aerospace to motorsport, industrial processes, and the energy industry,” a spokesman told Professional Engineering.

The engine is designed for a single-stage spaceplane, capable of flight in the atmosphere and space. Reaction Engines has received support from the UK and European space agencies, investment from companies including BAE Systems and Rolls-Royce, and the test programme at the company’s Colorado site is supported by the Defence Advanced Research Projects Agency (Darpa).

“This is a momentous landmark for Reaction Engines in the development of its Sabre engine, which has the potential to revolutionise both access to space and high-speed flight by powering aircraft to five-times the speed of sound,” said Reaction Engines co-founder and chief technology officer Richard Varvill.