RTX’s Pratt & Whitney business has completed a series of tests on its rotating detonation engine (RDE) work with the RTX Technology Research Center, the company announced on 4 March 2025.
Positive test results are spurring additional internal investment as Pratt & Whitney works with US Department of Defense (DoD) to accelerate a path to an integrated engine and vehicle ground test in the coming years.
Rotating detonation engines differ from traditional turbojet or turbofan engines in that they utilise a different thermodynamic cycle and require no moving parts, meaning they can be both lighter and more powerful than traditional engines.
The result is high thermal efficiency and performance, which allows for a small, compact and cost-effective engine. These attributes create room for additional fuel, sensors and payload, facilitating longer ranges and increased capabilities for air vehicles such as missiles that are critical to future defence applications.
“Our testing simulated aggressive assumptions for how and where the rotating detonation engine needs to perform,” Chris Hugill, senior director at Pratt & Whitney’s GatorWorks prototyping arm, was quoted as saying in a company press release. “This testing validated key elements of Pratt & Whitney’s design approach and provides substantiation to continue RTX vehicle and propulsion integration to accelerate future capabilities for our customers.”
In a rotating detonation engine the combustion occurs in an enclosed, ring-shaped chamber. In flight, fast-moving air is drawn into the chamber and a delicate mixture of fuel is injected. This injection ignites a flame-like detonation wave that travels around the ring for as long as fuel is injected, with the resultant energy converted to thrust that is used to propel the air vehicle.
