INTERNATIONAL
Chinese scientists build world’s first jet fuel-powered engine for Mach 16 flight
The world’s first oblique detonation engine (ODE) powered by standard aviation kerosene has been successfully tested by Chinese scientists, marking a potential gamechanger in hypersonic propulsion that could redefine the limits of air and space travel.
In a series of groundbreaking experiments at Beijing’s JF-12 shock tunnel, which simulates high-Mach flight conditions in altitudes of over 40km, researchers from the Chinese Academy of Sciences (CAS) achieved sustained oblique detonation waves using RP-3 jet fuel, a common commercial kerosene.
The results, published in China’s Journal of Experiments in Fluid Mechanics, suggest combustion rates 1,000 times faster than traditional scramjet engines, with operational capability between Mach 6 and Mach 16 – a speed where conventional air-breathing engines falter.
Unlike scramjets, which require bulky combustion chambers and struggle with flame-out risks at high Mach speeds, the ODE harnesses shock waves as allies.
By strategically positioning a 5mm bump on the combustor wall, engineers found they could induce self-sustaining “detonation diamonds” – ultrafast shock wave-fuelled explosions – that completed combustion in microseconds.
“The shock wave compresses and ignites the fuel-air mix so violently that it creates a selfreinforcing explosion front,” wrote the team led by Han Xin, lead researcher of the project with the CAS Institute of Mechanics.
At Mach 9, the tests revealed pressure spikes at detonation points reaching 20 times that of ambient levels, suggesting the engine was capable of generating a considerable thrust in a speed region where most scramjets could hardly breathe.
Due to the enormous power required, the wind tunnel supported only 50-millisecond sustained operation – equivalent to about 150 metres travelled at Mach 9 – but it was long enough for the researchers to get a full picture of the engine ignition and self-sustaining shock wave propulsion.
The new engine has a combustor that is 85 per cent shorter than a scramjet design, which can significantly reduce the weight of aircraft and extend flight range, according to Han and his colleagues.
For decades, hypersonic engines have relied on hydrogen or ethylene, but while they are fuels with quick ignition, they have impractical storage requirements. RP-3 kerosene, on the other hand, while logistically ideal with higher energy density, has long ignition delays that make the engine extremely difficult to start mid-flight.
But the CAS team has circumvented this by pre-compressing fuel-air mixtures to 3,800 Kelvin (3,527 degrees Celsius) before ignition, introducing a small bump that creates localised “hotspots” to trigger chain reactions, and accelerating fuel dispersion using wing-shaped struts.
The project is part of China’s ambitious plan to build a plane by 2030 that can reach anywhere in the world within an hour. At Mach 16 – about 20,000km/h, or Shanghai to Los Angeles in half an hour – the technology could enable reusable space planes bridging atmospheric and orbital flight.
If applied in military technology, the ODE engine could lead to a new generation of hypersonic missiles, drones or even bombers with ultra-long range and low operational cost that would give the People’s Liberation Army an edge in future warfare.
PR/ERMD
