In what may be a scientific first, Chinese aerospace experts claim to have developed the world’s first kerosene-burning Mach 9 jet engine.
The Chinese Academy of Sciences spent months fine-tuning the oblique detonation engine at the state-of-the-art JF-12 wind tunnel in Beijing, before publishing their findings in late November.
Hypersonic travel – along with semiconductors, robotics and AI – has been earmarked as a critical emerging technology and, as a result, has received significant funding over the past decade.
Breakthroughs in the field could become the difference between a flight time of hours and a flight time of minutes, between destinations.
The engine was described as a kerosene-powered detonation engine by peer-reviewed, Journal of Experiments in Fluid Mechanics. It was designed by Liu Yunfeng, a lead engineer representing the Chinese Academy of Sciences’ Institute of Mechanics.
While not new conceptually, examples and early designs of detonation engines in years gone by had predominantly been powered by hydrogen gas, which is both expensive and volatile.
The new design creates thrust through a series of explosions or detonations occurring rapidly within the system, instead of a constant burn.
Detonation engines were found to perform more effectively on similar fuel consumption, especially at speeds beyond Mach 8.
According to Liu, his team’s creation is the first working kerosene-fuelled detonation engine with hypersonic capabilities.
The kerosene-based fuel it burns is classified as RP-3 in China and is widely used to power Chinese commercial aircraft.
It was an ideal fuel choice because of its rich energy density and the relative ease at which it can be stored and transported, said Liu.
RP-3, which is comparable to the Jet A-1 fuel employed by the US aviation industry, is significantly more cost-effective than hydrogen-based fuel sources.
Kerosene does not combust as readily as hydrogen and Liu and his colleagues encountered difficulty detonating the fuel consistently during the testing period.
The team calculated that the combustion chamber would have to be enlarged by a factor of ten to facilitate positive results – an undertaking the research unit deemed impractical.
The solution came by way of a simple, thumbnail-sized fixture on the engine’s inlet. This relatively minor alteration allowed the kerosene and air mixture to interact more efficiently while maintaining the original combustion chamber dimensions.
Despite its military applications, hypersonic technology could revolutionise the commercial aviation sector, something the Chinese government has expressed interest in exploring.
Cutting travel times significantly bring about its obvious convenience, but some analysts have expressed concern over the operation and production costs.