Chinese Hypersonic Developments (HGVs/HCMs)

charles18

Junior Member
Registered Member
So far hypersonic ASMs are hypersonic only during high-altitude cruise. They are 3M in target area.
The density of air at 60,000 ft altitude is about 10% of that at sea level.
Less dense air = less air resistance = higher velocity
More dense air = more air resistance = lower velocity

The idea that a high flying hypersonic missile must slow down as it reaches near sea level altitude right before hitting its target sounds very believable.
 

taxiya

Brigadier
Registered Member
The density of air at 60,000 ft altitude is about 10% of that at sea level.
Less dense air = less air resistance = higher velocity
More dense air = more air resistance = lower velocity

The idea that a high flying hypersonic missile must slow down as it reaches near sea level altitude right before hitting its target sounds very believable.
I think the reason of having mach 3 upon impact is due to control limitation (smaller window for control system to adjust), not because of limitation imposed by air resistance.

The following paper is about boost-glide HGV, but it is good enough to show the impact of air resistance. You can see that if the initial velocity (end of hypersonic gliding phase) is 3000m/s, the impact velocity is 1800m/s which is still hyper-sonic > mach 5. If the initial velocity is 1500m/s, the impact velocity is just above 1200m/s (mach 3.5).

The second paragraph gives the reason of choosing mach 3.5 as having bigger transition window for reliable control.
1659549952933.png

On the other hand, if the war head is powered the impact velocity can be even higher than a glider, the only limitation is the challenge of control.
 

5unrise

Junior Member
Registered Member
The density of air at 60,000 ft altitude is about 10% of that at sea level.
Less dense air = less air resistance = higher velocity
More dense air = more air resistance = lower velocity

The idea that a high flying hypersonic missile must slow down as it reaches near sea level altitude right before hitting its target sounds very believable.
Just going to add another angle to the speed limitations of hypersonic weapons at sea level. If the missile descends to sea level prior to the terminal phase, with the trajectory being a sea-skimming one, going above Mach 3 will lead to plasma layers being formed in front of the projectile, which would interfere with radio signals. This would hamper the ability of the weapon's active radar seeker to lock onto its target at the terminal phase.

However, if the terminal trajectory is a near vertical dive onto the target from above, then only minimal course correction would be required and if even possible would need to be done at a high altitude. This means the projectile could maintain above Mach 3 at the terminal point. The Tsirkon still uses its scramjet engine at the terminal phase, suggesting its speed remains above 3M.
 

snake65

Junior Member
VIP Professional
Just going to add another angle to the speed limitations of hypersonic weapons at sea level. If the missile descends to sea level prior to the terminal phase, with the trajectory being a sea-skimming one, going above Mach 3 will lead to plasma layers being formed in front of the projectile, which would interfere with radio signals. This would hamper the ability of the weapon's active radar seeker to lock onto its target at the terminal phase.

However, if the terminal trajectory is a near vertical dive onto the target from above, then only minimal course correction would be required and if even possible would need to be done at a high altitude. This means the projectile could maintain above Mach 3 at the terminal point. The Tsirkon still uses its scramjet engine at the terminal phase, suggesting its speed remains above 3M.
The available videos of Tsirkon launches show a rather shallow terminal dive before impact and no sign of working engine. Iskander SRBM does a vertical terminal dive and still it's terminal velocity is 800 m/s. Just consider that Tsirkon is about the size of Onyx, where do you put the fuel to keep the engine running all the way?
 

sunnymaxi

Captain
Registered Member
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Chinese private firm joins hypersonic race​

  • TWR-Engine says it has completed ground tests on a revolutionary type of engine that could achieve speeds of Mach 5 or beyond
  • The Chongqing-based firm is a rare Chinese company working on the technology, which it one day hopes to mass-produce for drones and even aircraft
A Chinese engineering company says it has completed ground-testing of a prototype engine that it hopes will one day achieve
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with far better fuel efficiency than rocket or jet engines.
Chongqing-based TWR-Engine is one of the few private enterprises in China working in the field and is trying to develop a
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(RDE).
Commercial and military scientists in China and the United States are racing to perfect the RDE, which they hope will allow them to reach speeds of Mach 5 or beyond.

 

Overbom

Brigadier
Registered Member
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Chinese private firm joins hypersonic race​

  • TWR-Engine says it has completed ground tests on a revolutionary type of engine that could achieve speeds of Mach 5 or beyond
  • The Chongqing-based firm is a rare Chinese company working on the technology, which it one day hopes to mass-produce for drones and even aircraft

A Chinese engineering company says it has completed ground-testing of a prototype engine that it hopes will one day achieve
Please, Log in or Register to view URLs content!
with far better fuel efficiency than rocket or jet engines.​

Chongqing-based TWR-Engine is one of the few private enterprises in China working in the field and is trying to develop a
Please, Log in or Register to view URLs content!
(RDE).​

Commercial and military scientists in China and the United States are racing to perfect the RDE, which they hope will allow them to reach speeds of Mach 5 or beyond.​

Adding some more sections from the article
But they lack stable financial support, and their research needs a lot of investment.
“It’s hard to maintain stable combustion with a frequency of thousands of times per second.
There is a high demand for material to undertake the combustion shock wave, and such materials are always expensive,” said Hu.
But he said the team is full of confidence after completing ground tests last week, having carried out more than 30 tests on a fixed rail glider since December.
The team is now planning to carry out an aerial flight test by the end of this year with the eventual goal of mass-producing RDEs.
“We have faith in that. We have fewer limitations and a strong theoretical foundation. The talented team gives us solid support,” said Hu.
The team consists of talents from all relevant areas. We have engineers majoring in aircraft engines and missile experts from the army. Sixty per cent of team members hold a PhD”, said Hu.
Damn.. They got a real cutting edge team there
 

sunnymaxi

Captain
Registered Member
Adding some more sections from the article




Damn.. They got a real cutting edge team there
But they lack stable financial support, and their research needs a lot of investment..

this is why Beijing Stock Exchange has established. so far more than hundred SEMs listed and generate millions of Yuan. 70 firms are related to high tech. so they should register their company name and listed in BSE as soon as possible.

They really have a cutting edge team, with strong finance they can do wonders. insane
 
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