Chinese Hypersonic Developments (HGVs/HCMs)

From what I understand those engines do multiple timed detonations in sequence along an annular chamber.
But the basic operating physical principle is the same. It is just that because the combustion chamber is shared the shock is spread out over a larger volume and this likely reduces the overall vibrations. The result is probably less thrust per detonation, but a more stable engine that is easier to manufacture.

SEAD said:

Nope. The fire (burning region) ‘runs’ through a circle (drum), it’s not pulsed. There’re also oblique detonation engines, which are also continuous burning but the region is fixed.

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The pulsing refers to the release and/or ignition of fuel in periodic pulses. In RDEs the rotary drum is a mechanism to release fuel in periodic pulses. Similarly, the oblique shockwaves in an oblique detonation engine uses the periodicity of shockwave compressions to ignite the fuel in pulses. These are all forms of pulse detonation. What makes a pulse detonation engine a pulse detonation engine is periodicity of combustions.

latenlazy said:

In RDEs the rotary drum is a mechanism to release fuel in periodic pulses.

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No. I wonder if you have ever watched above quoted video or read any serious papers.
Fuel is injected CONTINUOUSLY (the position is changing but it’s continuous) from one side of the drum then after fire burns through, exhaust gas released from the other side of the drum. The whole burning process is CONTINUOUS and the fire ‘runs’ in circle (means you only need to IGNITE ONCE at the very beginning then it’s self sustaining), without any pulse.

SEAD said:

No. I wonder if you have ever watched above quoted video or read any serious papers.
Fuel is injected CONTINUOUSLY (the position is changing but it’s continuous) from one side of the drum then after fire burns through, exhaust gas released from the other side of the drum. The whole burning process is CONTINUOUS and the fire ‘runs’ in circle (means you only need to IGNITE ONCE at the very beginning then it’s self sustaining), without any pulse.

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I wonder if you’ve ever actually seen the insides of an RDE. The fuel is continuous but is *released* and *ignited* in pulses via a circular array of nozzles. The rotation combined with the nozzles basically create a periodic chain of detonations. Rotation of the nozzles create a pulsed sequence of explosions. Each of those explosions is an ignition. There is no ignite once and done in the engine.

latenlazy said:

I wonder if you’ve ever actually seen the insides of an RDE. The fuel is continuous but is *released* and *ignited* in pulses via a circular array of nozzles. The rotation combined with the nozzles basically create a periodic chain of detonations. Rotation of the nozzles create a pulsed sequence of explosions. Each of those explosions is an ignition. There is no ignite once and done in the engine.

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No ignition methods can work better than detonation wave.

Ok. I read this.

So basically those things on the bottom are fuel injectors. And the detonation is provided by the large perpendicular tube.
Supposedly only one detonation is needed and then the reaction is supposed to be self-sustaining.
And it turns out this is used for the engine core. And that then can be used on either a rocket or a ramjet like configuration.

I think the key innovation breakthroughs that are occurring now are related to cost, I have seen how they can very cheaply form titanium and rare earths into hypersonic aircraft parts, and now cheap sensor systems using Zinc glass instead of diamond.

They are combining hypersonics with rail guns, to provide very fast launches which cost very little in terms of electricity.

All of this will allow very cheap missile production, low launch costs, which will allow very large scale production.

If China simply upgrades their ship bourne supersonic ASMs to hypersonic ones, and does nothing else, they would be very likely to win any naval engagement and all US defenses would be basically useless.

I think they could do this right now, but why bother when you are still cutting costs massively, they know they can afford to wait.

My other thought is that these weapons will be made available for export to countries that sign up to the Global Security Initiative, along with ballistic missiles, radars and satellite data sharing. These things allow a country to be sovereign and bring balance to security situations, a stated goal.

Speaking of rotating detonation engines. Has this been shared?

Mianyang Aerodynamics Research Institute a test on a prototype RDE engine (running on ethylene and kerosene) that can reach a speed of mach 5.

Normally, I loathe to quote SCMP, but the original press release and news articles all seem to have been removed, leaving only some unclear regurgitations on the Chinese internet.

by78 said:

Speaking of rotating detonation engines. Has this been shared?

Mianyang Aerodynamics Research Institute

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a test on a prototype RDE engine (running on ethylene and kerosene) that can reach a speed of mach 5.

Normally, I loathe to quote SCMP, but the original press release and news articles all seem to have been removed, leaving only some unclear regurgitations on the Chinese internet.

Click to expand...

It's impossible to know who build the prototype. It's the largest testing centre. Which university build it will remain a question?

Chinese researchers say they have developed AI to predict course of hypersonic missiles​

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• Scientists from the Air Force Early Warning Academy say the technology can foresee the course of glide weapons travelling at more than five times the speed of sound
• The world’s leading powers are racing to develop hypersonic weapons and it is thought that existing technology will not be able to stop them

By Wednesday, 01 Jun 2022


Scientists from the Air Force Early Warning Academy say the technology can foresee the course of glide weapons travelling at more than five times the speed of sound. The world’s leading powers are racing to develop hypersonic weapons and it is thought that existing technology will not be able to stop them. — SCMP

Chinese military researchers say they have developed an artificial intelligence technology that can estimate the the course of a glide missile as it homes in on a target at more than five times the speed of sound.

An can estimate the incoming weapon’s potential kill trajectory and initiate a counter response with a three-minute lead time, according to the researchers.

The average missile stays within a target zone of 8km (5 miles), which is quite narrow for a weapon that can cover the distance in as few as two seconds.

“The world’s military powers are around the development of hypersonic glide vehicles, bringing new and severe challenges to air and space safety,” said Zhang Junbiao, a computer scientist from the early warning intelligence department of the Air Force Early Warning Academy in Wuhan.

“Trajectory prediction is of great significance to combat intent assessment and aerospace defence interception,” Zhang and his colleagues wrote in a paper published in the Journal Of Astronautics, a peer-reviewed publication run by the Chinese Society of Astronautics ,on April 30.



A hypersonic glide weapon launches an attack from space and unlike a conventional ballistic missile can travel in and out of the atmosphere like a stone skipping over water and bank to the left or right – making it harder to track and intercept.

At speeds of Mach 5 or higher it leaves little time for an air defence system to respond and it is generally believed that existing technology cannot stop a hypersonic glide missile.

But Zhang said AI could handle such uncertain tasks.

The defending side usually knows nothing about the mass, size, shape, aerodynamic control system or purpose of enemy weapons, but the AI can make a fairly accurate guess by analysing the observed flight data.

A missile, however advanced or fast, needs to obey certain physical laws, and every move it makes will give out some small but useful hints about its design, capabilities and mission, according to the researchers.

A machine learning algorithm can therefore learn from data collected in the early stages of a hypersonic flight, and use the newly acquired knowledge to calculate the most probable course in the final stages of the flight.

Zhang and his colleagues admitted that turning this theory into a practical model was not easy. They said the raw data collected by an early warning system contains lots of noise that could confuse the AI and too much data could also overwhelm the computer.
To counter this, the team developed a unique deep learning algorithm that could automatically remove noises from signals they detected. To save calculation resources, the algorithm also mimics the operation of the human brain by focusing only on the latest, most important data.

Though more sophisticated than any previous AI for hypersonic trajectory prediction, the new system can run on a laptop computer and produce a result within 15 seconds, according to the study.

Simulated tests suggested the method remains effective against a wide range of weapons flying at speeds of up to Mach 12.
, while the and carried out a successful test at Mach 5 earlier this month.

Military researchers have proposed numerous countermeasures, including space-based early warning systems that can detect and intercept the hypersonic weapon in the early or middle stage of flight, high-powered lasers that can blind or destroy sensors or missiles that can also operate at hypersonic speed.

But most of these technologies are still under development.

The Chinese navy has reportedly installed a new cannon in newer warships that it said could defeat a hypersonic weapon by firing 10,000 rounds of shells per minute at its predicted course.

A Beijing-based researcher involved in a military radar programme said AI would play a “big role” in hypersonic weapon defence but its effectiveness depended on many other factors.

A hypersonic missile, for instance, is surrounded by extremely hot, ionised gas that can distort the radar or heat signals, making precise detection of its movements difficult, according to the researcher.