According to the South China Morning Post, the revolutionary new engine is a standing oblique detonation ramjet (Sodramjet) design, with no moving parts, using the plane’s super-fast speed to push air into the chamber, where it is injected with hydrogen fuel and detonated, flying out the back of the engine as thrust.
That’s how all ramjets and scramjets work, which have been used to power missiles since the 1960s. However, the sodramjet design tested in the recent experiments improved on the concept “by replacing diffusive combustion with an oblique detonation that is a unique pressure-gain phenomenon in nature,” according to the abstract of a paper published by a group of Chinese scientists in the Chinese Journal of Aeronautics on Saturday.
“The Sodramjet engine model is developed with several flow control techniques, and tested successfully with the hypersonic flight-duplicated shock tunnel. The experimental data show that the Sodramjet engine model works steadily, and an oblique detonation can be made stationary in the engine combustor and is controllable. This research demonstrates the Sodramjet engine is a promising concept and can be operated stably with high thermal efficiency at hypersonic flow conditions,” the researchers noted.
The study authors found that the engine could operate at speeds of up to Mach 16, propelling an airframe around the globe in just two hours.
According to the SCMP, the Chinese scientists were likely inspired by the speculative work of Richard Morrison, an American engineer for the US National Aeronautics and Space Agency (NASA), who suggested the engine design in a 1980 paper that aimed to address problems created by a conventional scramjet design.
The paper noted that “the US government shifted the bulk of hypersonic research from Nasa to private companies such as Boeing and Lockheed Martin, and Morrison’s idea was largely if not completely forgotten by the American defense industry. The contractors put all their resources into scramjet design and continued to suffer setbacks that eventually caused them to trail other countries.”
China has claimed to already have hypersonic weapons and several other countries are said to be testing the technology, but a hypersonic vehicle that could carry humans remains an elusive piece of science fiction.
In April 2019, researchers at China’s Xiamen University tested a hypersonic aircraft named Jiageng-1 in the Gobi Desert, and in August 2018, tested a Starry-Sky “waverider” hypersonic vehicle. In the US, the US Air Force and the Presidential and Executive Airlift Directorate handed out a contract in August 2020 to develop a hypersonic airliner to serve as a future Air Force One for the US president.
Even for a hypersonic weapon, Mach 16 is very fast. China’s Dongfeng-17 hypersonic glide vehicle, a long-range strike weapon, is thought to be able to reach Mach 5. Russia’s Kinzhal hypersonic cruise missile has a similar speed, but Russian President Vladimir Putin suggested in 2018 that Moscow’s other hypersonic weapon, the Avangard glide vehicle, could reach speeds of Mach 20.
