Quickie
Colonel
Re: New Generation Fighter
That's a nice picture. A sign with Chinese characters would tell a lot.
That's a nice picture. A sign with Chinese characters would tell a lot.
J-20... The New Generation Fighter
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vesicles
Colonel
Re: New Generation Fighter
Anytime, an active-duty officer appears in front of a camera and gives an interview, he/she is representing the military/govn't, not himself/herself. My understanding is that any interview with the military anywhere in the world is "staged". I don't think you are allowed to say anything about the military to the public without proper authorization, no matter what nation you belong to. If the general said something spontaneously without authorization, especially something as important as the 4th generation fighter program, he would be disciplined by now.
Anytime, an active-duty officer appears in front of a camera and gives an interview, he/she is representing the military/govn't, not himself/herself. My understanding is that any interview with the military anywhere in the world is "staged". I don't think you are allowed to say anything about the military to the public without proper authorization, no matter what nation you belong to. If the general said something spontaneously without authorization, especially something as important as the 4th generation fighter program, he would be disciplined by now.
Re: New Generation Fighter
Also, on the subject of engine nozzels, how hard is it to replace the traditional round nozzel with a flatter rectangular one (and therefore more stealthy?) nozzel like that on the F-22?
I myself would rather be skeptical rather than sorry... So I have so say that nozzel looks a lot like the F-15S/TMD's 2Dimensional nozzels.
Also, on the subject of engine nozzels, how hard is it to replace the traditional round nozzel with a flatter rectangular one (and therefore more stealthy?) nozzel like that on the F-22?
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Infra_Man99
Banned Idiot
Re: New Generation Fighter
I checked your profile to search for other posts made by you regarding canards and TVC, and I couldn't find any detailed posts by you about candards and TVC. I found simple descriptions in a few posts made by you in the J-10 thread and in the New Generataion Fighter thread. The most informative post you made on canards and TVC is quoted first above.
I don't think canards and TVC are redundant. My understanding of horizontal stabilizers, canards, and vectored thrust:
Horizontal Stabilizers: when the leading edge is downward relative to the horizontal stabilizer's pivot point and it's moving through gas/liquid, then the horizontal stabilizer is pushed by the gas/liquid in a downward and backward direction. Mixed with wings, flight control, forward thrusting engines, and other control surfaces, the result is the airplane's tail moves down relative the airplane's front, which is an upward pitch.
Canards: when the leading edge is upward relative to the canard's pivot piont and it's moving through gas/liquid, then the canard is pushed by the gas/liquid in an upward and backward direction. Mixed with wings, flight control, forward thrusting engines, and other control surfaces, the result is the airplane's front moves upward relative to the airplane's rear, which is an upward pitch. Canards can improve the airflow over the wings (assuming the canards and wings are designed properly).
F-22's Vectored Thrust: when the exhaust nozzle points diagonally downward, the thrust effect is the airplane's rear moves upward relative to the airplane's front and the whole airplane moves forward. The aerodynamic effect of the downward nozzles is the airplane's rear is pushed by gas/liquid to move upward and backward. When the exhaust nozzle points diagonally upward, the thrust effect is the airplane's rear moves downward relative to the airplane's font and the whole airplane moves forward. The aerodynamic effect of the upward nozzles is the airplane's rear is pushed by the gas/liquid to move downward and backward. The net total effect of the F-22's vectored thrust is 2 possibilities: (1) the airplane is pushed forward and the airplane's rear is pushed upward (which pitches the airplane's front downward), or the airplane is pushed forward and the airplane's rear is pushed downward (which pitches the airplane's front upward).
I don't see how canards and TVC are redundant. They have similarities, but they also have significant differences. If the TVC is 3-D, multiple TVC are located far away from one another (i.e., the Harrier or F-25C), or asymmetrical 2-D (like on the Su-27), then the significant differences between canards and TVC are even bigger.
I checked your profile to search for other posts made by you regarding canards and TVC, and I couldn't find any detailed posts by you about candards and TVC. I found simple descriptions in a few posts made by you in the J-10 thread and in the New Generataion Fighter thread. The most informative post you made on canards and TVC is quoted first above.
I don't think canards and TVC are redundant. My understanding of horizontal stabilizers, canards, and vectored thrust:
Horizontal Stabilizers: when the leading edge is downward relative to the horizontal stabilizer's pivot point and it's moving through gas/liquid, then the horizontal stabilizer is pushed by the gas/liquid in a downward and backward direction. Mixed with wings, flight control, forward thrusting engines, and other control surfaces, the result is the airplane's tail moves down relative the airplane's front, which is an upward pitch.
Canards: when the leading edge is upward relative to the canard's pivot piont and it's moving through gas/liquid, then the canard is pushed by the gas/liquid in an upward and backward direction. Mixed with wings, flight control, forward thrusting engines, and other control surfaces, the result is the airplane's front moves upward relative to the airplane's rear, which is an upward pitch. Canards can improve the airflow over the wings (assuming the canards and wings are designed properly).
F-22's Vectored Thrust: when the exhaust nozzle points diagonally downward, the thrust effect is the airplane's rear moves upward relative to the airplane's front and the whole airplane moves forward. The aerodynamic effect of the downward nozzles is the airplane's rear is pushed by gas/liquid to move upward and backward. When the exhaust nozzle points diagonally upward, the thrust effect is the airplane's rear moves downward relative to the airplane's font and the whole airplane moves forward. The aerodynamic effect of the upward nozzles is the airplane's rear is pushed by the gas/liquid to move downward and backward. The net total effect of the F-22's vectored thrust is 2 possibilities: (1) the airplane is pushed forward and the airplane's rear is pushed upward (which pitches the airplane's front downward), or the airplane is pushed forward and the airplane's rear is pushed downward (which pitches the airplane's front upward).
I don't see how canards and TVC are redundant. They have similarities, but they also have significant differences. If the TVC is 3-D, multiple TVC are located far away from one another (i.e., the Harrier or F-25C), or asymmetrical 2-D (like on the Su-27), then the significant differences between canards and TVC are even bigger.
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Quickie
Colonel
Re: New Generation Fighter
My opinion is the canards and vectored thrust, working together, can do wonders to maneuoverbility, including sustained and instantaneous turning, though this could bring tremendous stress to the airframe. Perhaps both of them just have to move in smaller degrees. TVC actually doesn't improve payload in anyway but reduce the payload itself by being heavier than a normal engine. A more powerful engine would do a better job of improving payload.
My opinion is the canards and vectored thrust, working together, can do wonders to maneuoverbility, including sustained and instantaneous turning, though this could bring tremendous stress to the airframe. Perhaps both of them just have to move in smaller degrees. TVC actually doesn't improve payload in anyway but reduce the payload itself by being heavier than a normal engine. A more powerful engine would do a better job of improving payload.
Re: New Generation Fighter
Don't have much time to post a counter debate, but yes your right I couldn't find it in sinodefence forum, I could've mistaken it in either defencetalk forum for my previous post abou it. I'll get back to you later after I'm back.
Engineer
Major
Re: New Generation Fighter
If there is an unlimited amount of budget and payload capacity, then the two systems could supplement one another. However, in real life there are constraints on budget and payload, so the two systems would be competing with one another because they provide the same functions.
Elevators on fighters, and by extensions canards, can deflect independently and help contribute to roll moment as well. This isn't something exclusive to TVC. So no, that's not a "difference". Keep in mind that such advantage won't even exist on a single engine fighter.
If there is an unlimited amount of budget and payload capacity, then the two systems could supplement one another. However, in real life there are constraints on budget and payload, so the two systems would be competing with one another because they provide the same functions.
Infra_Man99
Banned Idiot
Re: New Generation Fighter
Whew, I just had a large Thanksgiving meal, so I'll try my best to sound logical.
I have no idea why you are replying to me, but I do have assumptions.
About using horizontal stabilizers, elevators, and canards for rolling/rotating an airplane: I already said this about 1 or 2 pages in the past.
In regard to budget concerns and payload capacity, these issues could create compromise or difficult decisions, but they don't create redundancy between horizontal stabilizers/elevators/canards and vectored thrust. The F-22, Harrier, and F-35C (whatever the VTOL F-25 is called) have horizontal stabilizers and vectored thrust to obtain various functions that cannot be fulfilled with using only horizontal stabilizers, elevators, and/or canards. In regard to only canards and vectored thrust, some Su-27 have canards, vectored thrust, and horizontal stabilizers to combine carrier landing/takeoff with agility across various speeds. The Eurofighter, a future J-10 derivative, and China's future stealth fighter jet may combine canards with vectored thrust to enhance agility.
Whew, I just had a large Thanksgiving meal, so I'll try my best to sound logical.
I have no idea why you are replying to me, but I do have assumptions.
About using horizontal stabilizers, elevators, and canards for rolling/rotating an airplane: I already said this about 1 or 2 pages in the past.
In regard to budget concerns and payload capacity, these issues could create compromise or difficult decisions, but they don't create redundancy between horizontal stabilizers/elevators/canards and vectored thrust. The F-22, Harrier, and F-35C (whatever the VTOL F-25 is called) have horizontal stabilizers and vectored thrust to obtain various functions that cannot be fulfilled with using only horizontal stabilizers, elevators, and/or canards. In regard to only canards and vectored thrust, some Su-27 have canards, vectored thrust, and horizontal stabilizers to combine carrier landing/takeoff with agility across various speeds. The Eurofighter, a future J-10 derivative, and China's future stealth fighter jet may combine canards with vectored thrust to enhance agility.
Re: New Generation Fighter
While TVC, Canards and conventional stabilators do in essence the same thing, they all get there by different means, each having it's on (dis)advantages.
Turning is basiclly climbing around a circle. To climb at a given speed, an aircraft has to increase the lift it produces. This is done by inreasing the AOA of the main wing, hence pitch up. To do that, conventional designs use their stabilators to create downward lift at the tail, moving the A/C around it's lateral axis. This decreases the overall lift produced by the A/C. So every conventional design will initially loose (a little) altitude before the increased AOA of the main wing can make up for that and produce enough lift to climb again.
Similar for TVC, the upward deflected amount of thrust in a pitch up controll input will effectivly increase the weight on the tail to rotate the A/C around the lateral axis. This means the main wing has to overcome that extra weight plus the increased lift requirement to turn/climb.
Canards, on the other hand, produce upward lift to pull the nose up, instead of pushing the tail down, so there's no lift penatly associated with them.
Then again, canards and stabilators are aerodynamic controll surfaces. That means they require a sufficient airflow to work properly. In slow speed situations, controll effectiveness might be severly decreased, a potentialy dangerous situation. TCV on the other hand provides controll authority even at very slow speeds.
And finally, canards and stabilators, by producing aerodynamic lift, also inherently produce induced drag (everytime they produce lift). TVC, however, won't produce induced drag, although I think there are also losses in thrust when the exhaust is deflected.
I've read somewhere that should the EF be equiped with TVC, this could take over trimming the A/C in supersonic speeds, reducing induced drag by 2%. (Or maybe reduce total drag by 2% due to the reduced induced drag?)
So I guess someone in R&D needs to figure out wich setup gives the most benefits and the least penalties, and what other tradeoffs (weight, cost) these improvements are worth.
While TVC, Canards and conventional stabilators do in essence the same thing, they all get there by different means, each having it's on (dis)advantages.
Turning is basiclly climbing around a circle. To climb at a given speed, an aircraft has to increase the lift it produces. This is done by inreasing the AOA of the main wing, hence pitch up. To do that, conventional designs use their stabilators to create downward lift at the tail, moving the A/C around it's lateral axis. This decreases the overall lift produced by the A/C. So every conventional design will initially loose (a little) altitude before the increased AOA of the main wing can make up for that and produce enough lift to climb again.
Similar for TVC, the upward deflected amount of thrust in a pitch up controll input will effectivly increase the weight on the tail to rotate the A/C around the lateral axis. This means the main wing has to overcome that extra weight plus the increased lift requirement to turn/climb.
Canards, on the other hand, produce upward lift to pull the nose up, instead of pushing the tail down, so there's no lift penatly associated with them.
Then again, canards and stabilators are aerodynamic controll surfaces. That means they require a sufficient airflow to work properly. In slow speed situations, controll effectiveness might be severly decreased, a potentialy dangerous situation. TCV on the other hand provides controll authority even at very slow speeds.
And finally, canards and stabilators, by producing aerodynamic lift, also inherently produce induced drag (everytime they produce lift). TVC, however, won't produce induced drag, although I think there are also losses in thrust when the exhaust is deflected.
I've read somewhere that should the EF be equiped with TVC, this could take over trimming the A/C in supersonic speeds, reducing induced drag by 2%. (Or maybe reduce total drag by 2% due to the reduced induced drag?)
So I guess someone in R&D needs to figure out wich setup gives the most benefits and the least penalties, and what other tradeoffs (weight, cost) these improvements are worth.
sidewinder01
Junior Member
Re: New Generation Fighter
Guys I know this may sound very obvious right now to you guys but I am still confused about this : Is China gonna test flight a 3.5gen modified version of J-10 or a 4th stealth fighter like the f-22 in the time announced by the vice Air Force Commander??!
Guys I know this may sound very obvious right now to you guys but I am still confused about this : Is China gonna test flight a 3.5gen modified version of J-10 or a 4th stealth fighter like the f-22 in the time announced by the vice Air Force Commander??!
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