Reaction Engines UK has launched a new testing campaign to dramatically expand its high-speed automatic propulsion technology, hoping to prove it can upgrade existing jet engines to be able to operate from take-off speeds up to Mach 4 and beyond.
The new tests are being conducted jointly with the US Department of Defense and the US Air Force Research Laboratory (AFRL) as part of a foreign comparative testing program used by the US military to identify high TRL (Technological Readiness Level) technologies that can “meet current and emerging requirements quickly and economically.”
The technology in question is the innovative precooler that forms a key part of Reaction’s vaunted SABER, or Synergetic Air Breathing Rocket Engine. The SABER engine, still in development, is a hybrid jet/rocket engine that promises to function as a hypersonic jet to fly supersonic speeds up to Mach 5 in the atmosphere, then launch its rockets to accelerate to Mach 25 “to reach space”.
Those speeds would be completely unthinkable without Reaction’s exceptional pre-cooler, a type of steroid-powered coolant whose job it is to receive a supersonic flow of air, heated to temperatures in excess of 1,000°C as the air flows with the aircraft. At Mach 5 speeds, it cools to -150°C faster than the blink of an eye, so it doesn’t instantly melt the engine’s internals as it goes by.
So it needs a large surface area, which it achieves by using thousands upon thousands of thin-walled tubes, through which the refrigerant is driven at high pressure, with no critical factor leakage. Reaction says it has found a way to connect all of these refrigerant tubes to the inlet and outlet manifolds in a single operation that eliminates leaks.
The company successfully tested the Mach 5 precooler in ground tests in 2019, and this new pilot campaign, to be held in Colorado in the coming weeks, will build on this work, increasing the mass airflow rate and other test criteria to provide a “three-fold increase in The total energy transfer through the engine heat exchanger”.
In the Defense Department’s view, these tests are designed to assess whether a precooler can be incorporated into other high-quality jet engines, which could open a rapid path to higher speeds than it is currently capable of handling. “The exciting result I’m looking forward to in the coming weeks is verification that our technology can allow current jet engines to operate from takeoff to Mach 4 and beyond,” said Andrew Beauty, director of interaction engineering, in a statement to the press.
