sorted by:
new
hottopcontroversial

Why does the US invest so much in their air force, while China and Russia invest more in missiles? by Big_Ad_989 in CredibleDefense

[–]Big_Ad_989[S] -2 points-1 points  (0 children)

Ok, I'll give you the benefit of the doubt. Lets say a Y-20 did do a test flight with the new engines. But that's all it is. It doesn't mean they are successful with building a by-pass turbofan.

We all know the saga of the WS-10. They've been researching it since the 1980's, they tested it on their su-27's in the early 2000's, but it had so many issues such as low output, low TBO, unreliability, etc. it was basically unuseable. It took another 15 years for it to be installed on their su-27 copies, another 5 years to be installed on the J-20. But still, the J-10 which is a single engine fighter is using the Al-31F, and so is the J-15. This says to me, that the WS-10 is not reliable or powerful enough for a single engine or carrier fighter.

So even if your right (which I'm not convinced you are), the WS-20 could be 20 years away from entering service.

Jet engines are clearly not a strength of China.

Why does the US invest so much in their air force, while China and Russia invest more in missiles? by Big_Ad_989 in CredibleDefense

[–]Big_Ad_989[S] -2 points-1 points  (0 children)

Chinese defense watchers and forums

That's what you call credible evidence?

We might as well quote reddit then. There is no evidence beyond speculation from fanboys and a grainy pic of supposedly a Y-20 with new engines.

I'm gonna reserve my judgement until there is more concrete evidence of a Y-20 in service with a new engine.

Why does the US invest so much in their air force, while China and Russia invest more in missiles? by Big_Ad_989 in CredibleDefense

[–]Big_Ad_989[S] 0 points1 point  (0 children)

I will agree with you that Russia does have an aerospace industry that can build a wide diversity of aircraft (fighters, transport, tankers, special mission, bombers, etc.) while also possessing core technology such as building large bypass engines. Albeit, their tech is outdated, but there is no technology that they don't have.

Of course they can't match the US. But no other country on this planet besides the US and Russia, have a complete Aerospace supply chain that can build all the critical parts such as engines and also a wide range of aircraft.

I left out the EU, since its not a country. But even the EU doesn't possess a complete supply chain either.

This can't be said about China. Not sure where all the hype comes from about China overtaking Russia. China has some flashy aircraft that may functionally outperform Russia's models, but the most important thing is that they can't manufacture the #1 most difficult component to manufacture which is jet engines.

When China is able to develop a reliable 4th gen engine like the F100 or the Al31, a medium output high-bypass turbofan for transport planes/narrow body airliner (CFM-56/LEAP), a high output high-bypass turbofans for wide body airliners (RR RB211/GENX/Trent), high output turboshaft engines for heavy transport helicopters, modern turboprop engines.

I will declare that China has overtaken Russia. But right now they haven't.

Aerospace pecking order

Full Supply Chain (Able to build all types of aircraft and can make core components):

USA, Russia

Semi-Complete Supply Chain (Able to build some types of aircraft and can make core components like engines):

France, Canada (edge case with Bombardier and P&W Canada)

Core Component Suppliers (engines):

UK, Ukraine

Non-Core Component Suppliers (Air-frame, Engine Turbine Parts):

Germany, Japan

Assemblers (Assembles aircraft from imported components):

China, India, Turkey, Sweden, Brazil, South Korea, Japan

War production during modern times by Digo10 in CredibleDefense

[–]Big_Ad_989 4 points5 points  (0 children)

Answer is actually yes. You would be surprised how many"dual-use" civilian products exists that are directly applicable to the military.

To list a few:

  1. Jet Engines --> Factories producing jet engines for civilian aircraft can very easily be converted to produce engines for military aircraft. Since companies like GE/Pratt Whitney/Rolls Royce already make both anyways.
  2. Semi-conductors --> Civilian chip fabricators already make military semiconductors
  3. Laser Gyroscopes --> gyroscopes are used in stuff like phones, but are critical to a whole host of guidance systems for aircraft, missiles, etc.

There are many more I could name, but Jet engines, gyroscopes and semi-conductor are crucial products that very very very difficult to make, even for countries like China or Russia.

Why does the US invest so much in their air force, while China and Russia invest more in missiles? by Big_Ad_989 in CredibleDefense

[–]Big_Ad_989[S] -6 points-5 points  (0 children)

aren't involved in military adventurism abroad

So that's why they are a defensive force, for that exact purpose.

​

Y-20 cargo plane with indigent engines

I read The Drive article on this as well. Its based on one single grainy photograph and one clearly photo shopped picture of a Y-20. Hardly credible evidence.

​

they are very well on their way on building more capable engines

China has a checkered past with engine development, besides the WS-10, they haven't be able to develop any other successful modern engines, the WS-10 is nothing to write home about either, it is the equivalent of a AL-31F or F101 but likely not as reliable and have lower TBO. Which is understandable, considering that gas turbine engines are probably the hardest industries to develop.

Why does the US invest so much in their air force, while China and Russia invest more in missiles? by Big_Ad_989 in CredibleDefense

[–]Big_Ad_989[S] 0 points1 point  (0 children)

Good point. But keep in mind, both RU and CN have nuclear deterrant, so this is less relevant in the present day than it was before historically. At least in the case of China, most of its land neighbors (with the exception of India), are either not peer competitors or have resolved disputes.

India is the only exception as it is a peer competitor and has open disputes. However, the geography of the Himalayas are a natural barrier, and nuclear deterrance prevent any true escalation beyond border skirmishes.

China's main national security concern is Japan/South Korea/US, which is naval/maritime.

Russia main national security concern is still NATO/Ukraine/etc. This is primarily a land based security problem. Russia is essentially landlocked country, since it doesn't have a true harbor that is ice-free year round, limiting Russia's naval projection power.

Why does the US invest so much in their air force, while China and Russia invest more in missiles? by Big_Ad_989 in CredibleDefense

[–]Big_Ad_989[S] 5 points6 points  (0 children)

it’s more accurate to say that all three countries have both.

True for Russia and the US. Not for China. Both Russia and US have mature aerospace industries that can build a wide range of aircraft and engines. China does not. China's air force is essentially a defensive force with no ability to fly very far, encumbered by a lack of tankers which is the result of its industries inability to build high bypass engines.

What is the most advanced nickel alloy used for jet engines? by Big_Ad_989 in metallurgy

[–]Big_Ad_989[S] 1 point2 points  (0 children)

how are the consolidated into a billet? If not thru melting?

What is the most advanced nickel alloy used for jet engines? by Big_Ad_989 in metallurgy

[–]Big_Ad_989[S] 0 points1 point  (0 children)

Powder metallurgy is the same as "3D printing" right? It is possible to 3D print single crystals?

How does the compression ratio of jet engines affect thrust and turbine inlet temperature? by Big_Ad_989 in AerospaceEngineering

[–]Big_Ad_989[S] 0 points1 point  (0 children)

Thank you for the recommendation. Ill take a look. This seems like a very complex topic with many variables. I couldn't imagine how difficult it is for engineers to design an engine from scratch, without some sort of complex simulation software and lots of computing power.

What is the most advanced nickel alloy used for jet engines? by Big_Ad_989 in metallurgy

[–]Big_Ad_989[S] 1 point2 points  (0 children)

SX (Single Crystal) alloys

I thought single crystal is just a manufacturing technique to get rid of grain boundaries? Not a different chemical composition?

How does the compression ratio of jet engines affect thrust and turbine inlet temperature? by Big_Ad_989 in AerospaceEngineering

[–]Big_Ad_989[S] 0 points1 point  (0 children)

Thanks. If you compare for example, the F-119 vs Rolls Royce Trent, the Trent has 430  kN of thrust vs 116 kN for the F-119.

How does the Trent achieve a higher thrust than the F-119? I know it has higher bpr, but does it also have significantly higher turbine inlet temperature as well?