This one. The canard were deflected downward which means the pilot was pushing the nose downward during a turning maneuver. Not logical at all.
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J-20... The New Generation Fighter III
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This one. The canard were deflected downward which means the pilot was pushing the nose downward during a turning maneuver. Not logical at all.
Popeye deleted the thread since he was fed up with people hotlinking photos and videos there. Sorry.
Thats basically right, however with a very sophisticated system like the J-20s, the stick or rudder pedals communicate the pilots desires to the FCS, the FCS then issues appropriate commands to each flight control surface needed to execute that manuever, if the pilot wishes to roll the aircraft 360 degrees as rapidly as possible,,, he will likely pitch the nose up 10 to 15 degrees in order not to loose altitude, and deflect the ailerons fully in the direction of the roll and that is a very simple explanation, in reality, with older aircraft you would step on opposite rudder to hold your heading as you initiated the roll, gradually easing off the opposite rudder to approximately nuetral when you were inverted.So your wings level upside down, in a nicely harmonized aircraft, a little [or a lot] of forward stick will maintain that 10 degree pitch up to maintain altitude, but we are rolling rapidly, in our older aircraft we would then step on the opposite rudder to maintain that 10 degree nose up attitude and as we approached wings level we would be decreasing aileron and rudder deflection. Are you confused, good, it took some thought and a lot of "finese" to perform this smoothly and precisely in a fluid manner. As a rule of thumb, the older and lower performance aircraft that you tried this in the more finese and feel this would take. So your good friend the engineer says, siege, I can help you, and you think how is he going to help me, but he designs a flight control system that "knows" what you want, you slap the stick over as you pitch up slighty and the computer does the rest. Your buds or your girlfriend think, that siege is a hot dog, he sure can handle that bird, you and your bud the engineer both feel good, because he has just reduced your work load by a factor of say 100, even if your in a dive at 1000 knots and pull back as hard as you can on the stick, your friend the engineer has programmed the FCS to a limit of 9 gs and you can't break your bird of black yourself out into oblivion. In spite of i.e. saying the flight control is easy, for him maybe, but he just told us all we were wrong, so maybe he's not as humble as we thought LOL. So give the airplane the command to role, call that "master input" with the stick, as the computer begins to execute the roll, it is receiving data from all the flight control, sensors, airspeed indicator, g meter, engine settings, etc etc etc etc, call these "secondary inputs" or if you'd rather "feedback", so you are in control of the computer or computers, and the computer is in control of the airplane. Now lets see how stupid this sounded to everyone else, but I hope you are catching a glimpse of how "smart" the J-20 is, but in fairness, even most fourth gen airplanes are smart.
---------- Post added at 10:04 PM ---------- Previous post was at 09:55 PM ----------
As usual sir, you are quite right, I used the archaic term slats, because they both increase the camber of the wing, and hence its lift, improving high alpha performance as opposed to no slats or leading edge flaps. Thanks Brat
^^ Being a programmer myself I think I can appreciate the difficulty of trying to code a FBW system on modern fighter jets. One little screw up and it is basically game over for the pilot.
As usual sir, you are quite right, I used the archaic term slats, because they both increase the camber of the wing, and hence its lift, improving high alpha performance as opposed to no slats or leading edge flaps. Thanks Brat
MiG-29
Banned Idiot
i want to ask this you asked why the J-20 does not use tail on a turn is my answer off topic and why is off topic if here you have plenty of aerodynamic answer?
I answered you true probably is not what you wanted, but the paper says limiting the elevons have a nose down component that has to be balance by the canards, if the canards need to be deflected too much is result of the static stability of an aircraft or the wing loading.
The paper gives a perfect answer to the pictures of the J-20 deflecting its canard too much, and what surprised was the paper was written a year ago before these test flights
---------- Post added at 10:15 PM ---------- Previous post was at 10:11 PM ----------
if you see an aircraft at high AoA the canard is not deflected downward to push the nose down, but in a higher unstalled position, the canard has a lower AoA than the aircraft
The problem isn't the off topic question, but the many following answers and counter questions. And no offense but it usually comes from you
Which is why I suggested creation of another dedicated thread.
But then people will only hotlink photos and videos onto the main J-20 thread instead? The posts are still going to happen but preferably not pages and pages of enlightening but divergent aerodynamic discussion.
If you think a new thread is inappropriate then ok.
The problem isn't the off topic question, but the many following answers and counter questions. And no offense but it usually comes from you
Which is why I suggested creation of another dedicated thread.
But then people will only hotlink photos and videos onto the main J-20 thread instead? The posts are still going to happen but preferably not pages and pages of enlightening but divergent aerodynamic discussion.
If you think a new thread is inappropriate then ok.
Good point. I'll ask popeye and see if he agrees.
You've got that right my boy, now me being an analog troglodite, it makes my jaw drag the floor, but the flight controls move very slightly in order to prevent those large excursions, whereas you might see a pilot having to make a gross control movement to correct the deviation that he didn't notice, because he was watching that F-22 on his tail, or T-50, or J-20. Thats why earlier in this thread, I noted the nice rolls the J-20 was performing and complimented the flight control system. I knew most of this stuff 35 years ago, but this forum has kinda nocked off the rust. Thank you all for translating Dr. Songs paper, I can wrap my mind around this stuff, because he takes it out of the realm of numbers and vectors and formulas, and is able to relate it into "pilot talk". In order to be a good pilot, you have to be an amatuer aeronautics engineer, and probably the most important principle besides "bernoulis theorum" is an understanding of angle of attack, something I didn't truly grasp until I read an article by a navy fighter pilot, in "pilot talk" and the light bulb came on.
MiG-29
Banned Idiot
The problem isn't the off topic question, but the many following answers and counter questions. And no offense but it usually comes from you
Which is why I suggested creation of another dedicated thread.
But then people will only hotlink photos and videos onto the main J-20 thread instead? The posts are still going to happen but preferably not pages and pages of enlightening but divergent aerodynamic discussion.
If you think a new thread is inappropriate then ok.
I am not off topic, or tell me is wrong to answer to siege his question?
Elevons are used as pitch control on tailess aircraft in example Mirage III/2000 or Kfir and if they are deployed as flaps the nose down force brings the nose down, the canard is pushing up, so you are simply making a rest, that is the reason why the jet is not using the elevons as pitch control or flaps.
If you checked the pictures the deflection of the canard is proportional to the static stability, canard position, lift, wing loading and other elements you do not know, you get upset because you can not even understand the logic of the canard deflection and elevon use on those pictures and i give an explanation, you just jump and say foul, he is breaking the rules, which i am not breaking, since even siege asked aerodynamic questions an many members are giving their explanation, what you are doing first is not of gentlemen, and second shows you are only willing to listen what you want to listen, not open to other opinions.
---------- Post added at 10:33 PM ---------- Previous post was at 10:31 PM ----------
i asked already, but if you are fair, your are also breaking the rules according to his points you asked aerodynamic questions then because you post videos, and you asked questions of aerodynamics, and by the way i have not posted a single hotlinked image
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