www.scmp.com
Point well taken
Or they both read the reports written and published in the 90s around innovative control effectors. The downsides of all moving tips are harder to spot from images / artwork.
Low thrust to weight ratio in aircraft like Mirage III, MiG-25 or SR-71 is not a problem to reach mach 2 or Mach 3, the problem is fuel consumption.
I'm not sure who you think you are arguing with. Noone is arguing three engines = high speed as far as I can see.
I don't understand this at all. Using any specific number of engines is not good or bad in isolation.
I agree with you, what I mean is explained by this:
It's not however with this design there's some imo pretty obvious reasons for this, since if the third engine's intake were to be on the bottom there would be no space for IWBs.
The other thing to point out to the beginners and armchair analysts is that sometimes you're arguing with a veteran engineer with a lifetime's experience versus that one book on aircraft design you kinda-sorta skimmed one time and opinions you formed from playing flight sims or watching Youtube videos.
If you allow a bit of a political/economic aside, this is the biggest issues with how the US does economics, and if they don't actually switch back to competitive capitalism, and/or manage to bully China into the ground, they're going to lose to them.Envoy says sloppy American defence firms pose ‘bigger risk’ for US than China
US envoy to Japan Rahm Emanuel said contractors prioritising stock buy-backs over timely arms deliveries could harm national security.
"In 2023, Lockheed Martin and RTX spent a combined total of US$18.9 billion on stock buy-backs, compared with just US$4.1 billion on capital expenditures, according to data compiled by Bloomberg."
Focus on the dividends.............
Regards,
imo at this stage of things, I don't think any levelheaded individual that has basically any sense of engineering or common sense thinks that way anymore.
Or Westlands/Shorts in the UK flying multiple aircraft with these as the primary controls back in the 30s - 50s
aviationweek.com
The position some people took in this topic is too simplistic, amateurish I might say. To claim that the Chinese had to implement a 3 engine configuration because 2 has insufficient thrust would imply that they had already experimented with a 2-engine setup, found it lacking and modified the airframe to accept a new engine slotted in the centerline. So, the base air vehicle had insufficient thrust margins but somehow enough for drag and structural integrity? And, say, they couldn't have went for a more powerful engine (couple existing core with larger fan ala F401, or goes VCE) or dumb down the specs? Those stuff are discussed at the earliest trade studies. And we don't even know the objective specs yet. If the RFI said XXX thrust and basic math says 2 WS-15 has XXX/2 thrust why would they even bother with a 2 engine config. There are also timelines and growth requirement. Say, the demo vehicle only needs XXX/4 tons of thrust, so CAC could use WS-10s and switch in VCEs later on when they start putting in more electronics.
My old company HR (Hydraulic Research) Textron (now Woodward) had developed some developmental fluidic flight control actuators back in the 1980s and I think some were tested by Northrop and NASA. Everybody was hot for fluidics back then but it died, no takers. Seemed to work well from what I understand. HR had also developed a fluidic actuation control "logic computer" but again, went by the wayside unfortunately.
The end of cold war and its consequences.
Hydroman, So when I found the PW work for three stream NGAP Tech, it was described that the third stream could be used for fluidic control, I feel there may be a revival! Article Number is in the image info.
Actually, don't you guys think the exhaust looks similar to the design of the J-36's exhaust, with an actuated lower flap extending over the top? Imo if these speculation about exotic flight control techniques turns out to be true, the J-36 prototype might be the single most advanced fighter(prototype) in terms of aerodynamics that has ever publicly flown.
If I understood this well, you are saying that the most likely reason the third engine is there so neither has to work with an afterburner therefore working in the most optimal regime to achieve flight parameters? Plus, as you and others have said already, all aircraft engines already produce electricity as their primary function so reserving one for that function alone might not be very practical?
I don't think he is arguing. He was answering my question. I am quite new and did not understand what he and some others meant with their posts. Now it is clear. Cheers
There should also be a consideration for reserve electrical power. What I mean is that if 6th generation will sport laser weapons and high-frequency radars, one would need a lot of reserve power to ramp up when targeting stealth or firing lasers. That could also be a potential reason to add a third engine?
Imo the middle engine could very well be a "generator" engine in the sense that it has a couple of extra generators coupled on to it but otherwise could probably still be disengaged from the extra generators with some kind of clutch and function normally like the other 2 when high thrust is required. Also I think the J-36 not having afterburners seems unlikely, since even though it could supercruise having afterburners is still quite helpful if you want to take off with a large weapons load without needing an excessively long runway or improve short field take off performance in war time when longer airfields are not available, also I feel like it might also be helpful if they needed to quickly retreat having burners would probably allow a high dash speed(Faster than supercruise speed) for the aircraft to get to safety or when they need to do some hard maneuvering and retain energy imo.
Agreed. That does make sense. Practical and pragmatic system implementation. Double and triple the designed use case whenever possible.
The HR fluidic actuators were high hydraulic pressure units and initially being looked at for backup redundancy only. Fluidic logic is used in current hydraulic restrictor valves where very stable, controlled flow has to be precise over long periods of time vs. the traditional knife-edge hydraulic orifices, traditional orifices erode in time thus allowing unwanted increases in flow and affecting performance.
The DARPA CRANE program seems to be using another variation of distributed bleed air fluidics coupled with the Coanda Effect in relation to boundary layer disruption and control for 6DOF flight controls. It will be interesting when they begin flying. But with that said and from a systems design viewpoint, you now have to have a series of electropneumatic control valves for controlling and managing air flow to the what I call "Air Surfaces" and for an operational platform, must have redundancy. You also have distributed ducting which is larger than hydraulic tubes and can take up more envelope.
Chinese engines have in fact been more reliable than Russian ones from what I know, as the J-10s still mostly powered by AL-31s have crashed a few times due to engine trouble while the Sino-flankers which has been using WS-10 variants for nearly two decade has to my knowledge never have a crash specifically attributed to engine issues. Also imo Chinese building substandard stuff have been mostly disproven especially for their own use. FYI China actually has been making their own engines although at first mostly licensed clones or modified/improved variants of Soviet engines since the 60s, so they actually are quite experienced in making engines contrary to what most people believe.
I will not claim to have looked deep into that topic and have a very valuable opinion, but if you have (in the future) DEW and some other extremely high power applications onboard, you will probably develop (also in the future) an engine that is optimized for power generation, maybe supported by some purpose designed APU and accumulation system, to get a practical solution. But to add an engine just for that would not seem the best engineering solution to me, too many downsides IMHO to be worth it.
Well remember to carry extra fuel and an extra engine when an engine off means lower thrust to weight ratio, each engine needs fuel.
That assessment is a forum assessment, in real life you need to see what export costumers say.
The DC-10 had three engines because of the regulations at the time (and being larger than the A-300..)
