Mach 30 speed
SCMP newspaper quoted Chinese Academy of Sciences researcher Han Guilai as saying in an online presentation in May that the JF-22 wind tunnel, in Beijing's Hoai Nhu district, is capable of simulating flights at Mach 30 (37,000km/h) - 30 times the speed of sound. Along with an existing facility, also in Beijing, the new wind tunnel will take China about 20 to 30 years ahead of the West.
Han Guilai, from the Institute of Mechanical Engineering - China's leading hypersonic research agency - said that the surface of a plane traveling at such a speed could reach 10,000 degrees Celsius - hot enough to break air molecules into atoms.
Han said: "This air is no longer the air we breathe. The flying vehicles we research are like swimming in mud.
Han said the energy generated by the JF-22 wind tunnel will reach 15 gigawatt - nearly 70% of the installed capacity of the world's largest hydroelectric plant, the Three Gorges Dam in Sichuan province, southwest China, or more than seven times the Hoover Dam in Nevada, US.
China, along with other major countries, has invested heavily in developing hypersonic flight technology, allowing tourists to land anywhere in the world in one or two hours. It will also cut the cost of space launches by more than 90%, potentially making space travel popular.
Commercial hypersonic aircraft
As China and the US compete for global technology leadership, the race to bring hypersonic flights to life is increasingly fierce.
Aerion, a private company that develops passenger supersonic aircraft based in Nevada, has encountered financial and technical problems this month. Last month, a highly anticipated hypersonic weapons test by the US Air Force ended in failure.
Supersonic testing began in the West in the late 1940, and American pilot William John Knight briefly achieved Mach 6.7 (8,200km/h) speeds in a rocket-powered X-15 test aircraft in the 1960s. Despite the early departure, Western countries still lack hypersonic vehicles.
China's hypersonic test flights have recorded unusually high success rates, with no plane crashes reported. In 2019, Chinese space authorities conducted a secret test of a prototype of a spacecraft that could take off or land at a regular airport. Researchers have also revealed details in domestic scientific journals about hypersonic engine designs that cannot be found anywhere else in the world.
Part of China's success in the field of hypersonic is thanks to the unique technology used in the country's wind tunnels. Unlike facilities in other countries that use mechanical compressors to create high-speed airflow the JF-22 uses chemical explosions.
When the tunnel caught fire, its fuel burned at a speed 100 million times faster than a gas stove, creating shock waves similar to those the plane encountered at super-fast speeds at high altitudes. According to Han, each aircraft "needs to conduct about 10,000 tests in the tunnel" before production.
Lens II, the most advanced wind tunnel in the US, has simulated flights up to Mach 7 (8,575km/h), with a simulation time of 30 mph. In contrast, the JF-22's average runtime could reach 130 mph, with a much higher maximum speed, Han said.
Our testing takes longer than theirs, so the model could be larger than theirs, and the experiments could be more advanced than theirs. This determines our top position in the world, Han said.
Qian Xuesen - the father of China's missile program - coined the term "supersonic" in a 1946 article after he discovered that airflow behavior follows completely different rules at a speed five times faster than sound.
Qian dged a big hole at the time, and now people from all over the world are jumping into the hole, Han, a fourth-generation hypersonic researcher after Qian started 60 years ago, said.
A supersonic physicist in Shanghai confirmed the information in Han's speech.
Although the launch date of the JF-22 is still kept confidential, it will work alongside the JF-12, an older tunnel with about a fifth of its power, to simulate flight conditions at both higher and lower altitudes, where air density is quite different, according to the researcher.
"There is a Chinese saying, to sharpen a sword takes 10 years. We have spent 60 years sharpening the two swords. And they are the sharpsest swords - Han vi von.
