China takes a step further in hypersonic propulsion, an ambitious race in which it competes with China to manufacture devices capable of striking the speed of sound when flying. And in one of its key pieces, in addition: the engines. A group of scientists from the Asian giant —advances the Hong Kong newspaper South China Morning Post— has developed the first hypersonic detonation wave engine capable of propelling flights at nine times the speed of sound (Mach9), which is equivalent to about 11,000 kilometers per hour, with low-cost jet fuel.
The researchers successfully completed several experiments with the detonation engine during its ground tests, carried out earlier this year at a special facility in Beijing.
The technical details of the device were specified in an article published in Journal of Experiments in Fluid Mechanics. In the report, the team led by Liu Yunfenf, an engineer at the Institute of Mechanics of the Chinese Academy of Sciences, explains that test results with motors of this type have never been published in which they were used. aviation kerosene.
An improvement in design
Detonation engines can offer greater efficiency than other alternatives for flights, such as the scramjet. The key: his ability to generate a series of explosions that in turn release a powerful flow of energy. The technology is by no means new and other detonation engines have already been tried. Of course, they mostly need hydrogen, a fuel with two important handicaps: its price and safety, given the risk of explosions.
Liu’s team – specifies the South China Morning Post— has wanted to focus on that weak point by using RP-3 for its engine, a fuel for jets that, among other peculiarities and compared to diesel fuel, shows a release of heat and retarded combustion.
The idea of the Asian team It’s not entirely new either.. Using jet fuel in hypersonic flight has long been considered by researchers, but translating it into practice has presented some major challenges for engineers: Its slower combustion than hydrogen requires significantly larger detonation chambers. And that, when it comes to hypersonic aircraft, in which every millimeter of surface counts, is a problem.
With a slight change for the air intake of the engine, however, the Chinese researchers have managed to facilitate the ignition of the kerosene, which avoids having to resort to large chambers that could compromise the design of the aircraft. Their proposal, they say, is pioneering.
The work of Liu’s team is part of the efforts developed inside and outside China to create robust propulsion systems for hypersonic and supersonic flights, a technology that would allow flying at high speeds and improve the efficiency of the entrances and exits of the atmosphere.
“The ability to base such a system on detonation, the most powerful form of combustion, has the potential to provide greater thermodynamic efficiency, higher reliability and reduced emissions”, explains a team of researchers at PAS.
China is not the only one working in the field.
Months ago, both the Asian giant and the US showed their progress with rotary detonation engines, a technology with a high thrust capacity and which would allow, in theory, speeds of Mach 17 with an added advantage in fuel economy.
In March his own South China Morning Post published that a team from Tsinghua University, in China, had developed a prototype that solved some problems of previous designs. In the United States, months ago they also pointed out the development of work on the rotary detonation engine and designs and prototypes of oblique detonations.
Hypersonic technology has interesting applications both civil, for transportation, and military. China has already developed several hypersonic missiles, such as the DF-17 and YJ-21.
Cover Image: Wikipedia
