The Chinese company Sichuan Lingkong Tianxing Technology presented a model of the hypersonic drone Cuantianhou (one of the names of the Monkey King) in Chengdu. The one-and-a-half-ton, seven-meter craft with two ramjet detonation engines will be able to accelerate to speeds in excess of Mach 4, which is twice as fast as the legendary Tu-144 and Concorde. The first tests were planned for 2027, but the developer announced that they would conduct them a year earlier.
Image source: Sichuan Lingkong Tianxing Technology
Successful launches of early prototypes and data collected during testing helped speed up testing. So, just last fall the company conducted two tests with real engine launches on simple models (actually in the form of rockets). In total, over the past six years, 88 tests have been carried out in combination with computer simulations.
All this suggests that hypersonic civil aviation is already on the horizon. Sichuan Lingkong Tianxing Technology plans to fly the prototype of the Da Sheng hypersonic passenger aircraft in 2030.
«Thanks to advances in noise reduction, materials science and flight control systems, the era of supersonic passenger flights is on the horizon,” Deng Fan, the company’s chief engineer, said at a press conference.
The developer noted the similarity of Cuantianhou with the American SR-71 Blackbird reconnaissance aircraft from the 60s of the last century. “It is very similar to the American SR-71 Blackbird, but its propulsion system, flight altitude and speed are significantly different,” Dan emphasized. The SR-71 Blackbird developed a speed of Mach 3.32, while the Cuantianhou at an altitude of 20 km will accelerate to Mach 4.2.
American companies such as Boom Supersonic and Hermeus use different technological approaches when designing civil supersonic aircraft. At the same time, the latter plans to launch a hypersonic aircraft at a speed of Mach 5, while the former plans to achieve a modest speed limit of Mach 1.7. There is also a Swiss startup called Destinus, which is studying hypersonic jet aircraft powered by hydrogen fuel. However, so far, not a single breakthrough commercial product has appeared anywhere except China. All of them are at least three years behind schedule, according to Chinese developers.
Also at the exhibition, Sichuan Lingkong Tianxing Technology showed a modernized detonation engine. Previously, Jindou-400 engines took part in the tests. Last June, the Jindou-400S engine was created with much better performance and an improved weight-to-thrust ratio. Thus, Jindou-400 weighed 300 kg with a length of 2.6 m and a thrust of 2.5 kN. The Jindou-400S engine weighs 100 kg, has a length of 1.9 m and develops a thrust of 4 kN. Both of them run on aviation kerosene. The Cuantianhou drone will have two such engines.
Operating principle of a rotary detonation jet engine
The savings in engine operation are particularly impressive. For 50 km of flight at a speed of Mach 4, fuel consumption was 6 kg. This is one of the advantages of detonation jet engines. The shock wave front during explosive detonation of fuel creates a more powerful jet stream than during direct combustion of fuel in conventional jet engines.