It is absolute nonsense to use the control mechanics of control surfaces as a way to draw any conclusions about performance regimes. A tail can subtract lift by deflection just as a canard can add lift by deflection, because as it turns out all maneuvers in all regimes requires some deflection of the control surface no matter which type of control surface you’re using.
J-20 5th Generation Fighter VII
- Thread starter siegecrossbow
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actually that small clip was not part of the first day's show, you can see the rotation started very soon after its climb-up but in the show of first day there is a significant interval between pulling-up and spinning. The video Red Tsunami linked above actually looks quite more impressive than anything we've had from fans/state media so far. Could just be shooting angles and positions or whatever but my guess is that the J-20 performed most of these "more impressive" maneuvers right at the end of the performing fly zone while most cameramen stopped tracking when they lost sight of it.
It seems only edges < 90 degrees are trimmed.
Wow, better than airshow performance.
I noticed that all the clipped tips are of angles less than 90 degrees. The un-clipped main wing tip at the back is actually larger than 90 degrees. Maybe the angel 90 degree is a critical threshold between stealth and aerodynamic demands.
About the famous smoke, I just searched youtube for F-22's airshow for comparison. Here is the full video
Here is a screen dump. There are many similar occasions. It is very visible when the aircraft banks and turns. Between 10:19 to 10:20 one can see the exact "spewing out smoke" as WS-10 and AL-31. I have also compared with the vortex at the edge of the wings at the same angle of light, it is darker and yellowish/dirty than white vortex.
The smoke is at least one or even two body length away from the nozzles. So if the video frame is close to the aircraft, one will never be able to see the smoke. That is probably why F-22's engine was regarded as cleaner than AL-31 or WS-10, because USAF has better PR department the camera man. On the other hand, those videos showing Russian and Chinese smokes are mostly made by amateurs or outsiders who has no access to a perfect photographing stand.
From a technical perspective, any engine using afterburner will have smoke at the first moment when large amount of fuel is suddenly pumped in the hot pipe that has almost no oxygen left because non-afterburning regime before it. When turning on afterburner, extra oxygen will be let in when injecting fuel, it takes time for oxygen to enter the chamber after turning on some valves. One may choose to turn on oxygen earlier than pumping fuel, but that will grantee a fixed delay. So the preferred way is to pump the fuel immediately and burn as soon as oxygen arrives. One may also argue to run oxygen rich at all time, that is very bad for the engine's life-span. I don't think any sane engineer is going to do that just for the sake of cleaner burn for a split of second to please the air-show watchers.
But regardless the technical options one may argue for, the smoke is clearly visible on F-22.
Here is a screen dump. There are many similar occasions. It is very visible when the aircraft banks and turns. Between 10:19 to 10:20 one can see the exact "spewing out smoke" as WS-10 and AL-31. I have also compared with the vortex at the edge of the wings at the same angle of light, it is darker and yellowish/dirty than white vortex.
The smoke is at least one or even two body length away from the nozzles. So if the video frame is close to the aircraft, one will never be able to see the smoke. That is probably why F-22's engine was regarded as cleaner than AL-31 or WS-10, because USAF has better PR department the camera man. On the other hand, those videos showing Russian and Chinese smokes are mostly made by amateurs or outsiders who has no access to a perfect photographing stand.
From a technical perspective, any engine using afterburner will have smoke at the first moment when large amount of fuel is suddenly pumped in the hot pipe that has almost no oxygen left because non-afterburning regime before it. When turning on afterburner, extra oxygen will be let in when injecting fuel, it takes time for oxygen to enter the chamber after turning on some valves. One may choose to turn on oxygen earlier than pumping fuel, but that will grantee a fixed delay. So the preferred way is to pump the fuel immediately and burn as soon as oxygen arrives. One may also argue to run oxygen rich at all time, that is very bad for the engine's life-span. I don't think any sane engineer is going to do that just for the sake of cleaner burn for a split of second to please the air-show watchers.
But regardless the technical options one may argue for, the smoke is clearly visible on F-22.
Even when the J-20 gets WS-15 it will probably still be smokey.
Smoke is just a fact of life I guess. Hoping all jets will use smokeless plasma thrusters before I kick the bucket.
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