Chinese scientists have announced the creation of a highly efficient hypersonic engine. This engine is unique as it operates with both a rotating detonation system and an oblique detonation system. In theory, this technological feat could enable an aircraft to reach Mach 16 at an altitude of approximately 98,425 feet (30 kilometers).
A Detonation Mode That Adapts to Motion
The type of detonation used in this new engine varies depending on the speed of the aircraft. Up to Mach 7, it operates on a rotary system. In this case, fuel and oxidizer are introduced into a space between two coaxial cylinders of different diameters, allowing continuous detonations to propagate around the channel, which gives the engine good efficiency, despite it being more unstable.
It should also be mentioned that several countries have already developed engine prototypes for aircraft or missiles using this system. However, beyond Mach 7, the mode changes, and the detonations no longer rotate. From that point, everything is concentrated on a circular platform at the back with oblique line detonations. It should also be clarified that with this phenomenon, fuel detonation occurs automatically due to one factor: the speed of the incoming air.
Addressing Bugs to Improve Technology
Nevertheless, the scientists note that this engine encounters problems around Mach 7, where the rotating detonation becomes unstable. This suggests that the oblique detonation mode should be activated more quickly. To try and correct this issue, they are considering several options. One of these is to reduce the speed of the incoming air from Mach 7 to Mach 4 or lower. This would allow the fuel to be heated sufficiently for self-ignition.
Another approach involves modifying the internal structure, such as altering the diameter of the circular platform or the angle of the shock wave. In both cases, the development of this technology marks a significant advancement in the scientific field. Once researchers design a more stable engine, it could pave the way for the creation of more efficient aircraft.