Re: J-20... The New Generation Fighter III
wow more flip flop.
Here is your typical tactic mixing sources to claim a source says other things
Nope. There is no flip flop. This is just your typical tactic of using silly little word-games to distort papers to suit your beliefs. Dr. Song has been pretty clear on the use of "unconventional aerodynamic control mechanisms" when talking about the canards:
As a result, it is vitally important to study unconventional aerodynamic control mechanisms for high AOA flights.
The article says
canard deflection (delta_c) influences the angle of attack in the below-stall range, see Fig-10, but does not influence in the post stall range.......
The
where you says that conventional control is lost at high AoA:
if the aircraft can fly at angles of attack of 80[SUP]o[/SUP] - 120[SUP]o[/SUP] with the ability to maintain stability in all channels. In this flight regime the ability for conventional control is usually lost.
Tailplane is part of those conventional controls, canard is not. The paper is even more explicitly by making the following statement:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
Thus, tailplane loses effectiveness at high AoA, which is the same the facts stated in Dr. Song's paper. It is because of that ineffectiveness that makes canard superior at high AoA, as canard doesn't encounter the same problem.
plus
if the aircraft can fly at angles of attack of 80o - 120o with the ability to maintain stability in all channels. In this flight regime the ability for conventional control is usually lost.
Correct! And by conventional control,
is referring to tailplanes, which is explicitly mentioned in the following statement:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
Thus tailplane cannot be used to control the aircraft at high AoA. This is why Su-27 has to keep the Cobra maneuver as short as possible. Aircraft that has TVC can be controlled at high AoA and aren't subjected to such time limitation.
a but as a good falacy you claim the article says canards work because Song paper hahaha
Nope. The only fallacies are those that made by you. Take the above statement for example, it is known as
. It is a fallacy because you are claiming I said "
says canards work", a statement that is actually your own invention.
What I have been saying is that tailplane is ineffective at high AoA, a fact pointed out by many of your own sources. Thus, canard is superior to tailplane as pointed out in Dr. Song's paper:
Control surfaces placed in front of the center of mass, like the canards, are negative load control surfaces. Since the main wing's ability to generate lift tends to saturate under high AOA conditions, the positive load control surfaces' pitch down control capabilities tend to saturate under high AOA as well. Therefore it will be wise to employ negative load control surfaces for pitch down control under high AOA conditions. Figure 7 compares the pitch down control capabilities of the canards and horizontal stabilizers. From the high AOA pitch down control stand point, it will be wise to use canards on the future fighter.
The article says canards do not work
you just make your own concept to say something the article does not say.
No where in
does it say canards do not work when the aircraft is in high AoA, and you haven't been able to provide an ounce of proof showing that the case. Furthermore, that same article makes the following statement:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
That tailplane loses effectiveness at high AoA is what I have pointed out repeatedly. And this is why the paper agrees with the facts stated in Dr. Song paper regarding inadequacy of the tailplane, debunking your claim otherwise.
you just make your own concept to say something the article does not say.
Nope. This is
of your own dishonesty on to others. You distort statements from the article to claim it says something that it does not say, so you assume others are doing the same thing.
What Song says in one article does not chance what the original author said
canard deflection (delta_c) influences the angle of attack in the below-stall range, see Fig-10, but does not influence in the post stall range.......
Well then, let's look at what the original authors from
says:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
Tailplane loses effectiveness at high AoA. This means active deflection of taliplane cannot be used to provide pitch moment at high AoA, and it is in agreement with Dr. Song's paper. It is because of this lost in effectiveness that makes tailplane inferior to canard at high AoA. From Dr. Song's paper:
Control surfaces placed in front of the center of mass, like the canards, are negative load control surfaces. Since the main wing's ability to generate lift tends to saturate under high AOA conditions, the positive load control surfaces' pitch down control capabilities tend to saturate under high AOA as well. Therefore it will be wise to employ negative load control surfaces for pitch down control under high AOA conditions. Figure 7 compares the pitch down control capabilities of the canards and horizontal stabilizers. From the high AOA pitch down control stand point, it will be wise to use canards on the future fighter.
as such your tactic is avoiding what the original source says trying to mix sources and linking them in a way you think your thesis is real hahaha.
You are the real verbosity fallacy maker
Since the original article does not say the canard work at post stall.
The
does not say canard doesn't work at post stall either. What the article does say is that tailplane loses effectiveness at high AoA:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
There is no fallacy involved in pointing out an explicit statement made by the author to debunk your claims. What this is called is pointing out facts and debunking your pseudo-aerodynamic theories.
It is you who does not quote that part and avoids it.
"Angle of Attack and tailplane deflection depend very strongly on the flight path angle in the post stall region, and practically do not depend in the below stall region
Nope. I quote that
very often. Here, I will do it again:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
Very strong deflection of the tailplane in the post-stall region is not a proof that tailplane is effective in providing pitch moment at high AoA. Indeed, from the above quote, you can see that paper is quite explicit at saying tailplane loses effectiveness at high AoA. This means tailplane cannot be used to provide pitch moment at high AoA, thus debunking your claim.
"third phase, (recovery from the manoeuvre) characterised by full deflection of the horizontal tail for diving with the increasing,"
The same
from which you extracted the above quotes from also says this:
It can be explained by loosing of effectiveness of control surfaces... In the range of AoA up to 35[SUP]o[/SUP] the normal increases approximately linearly, then stabilises and practically the tail surface losses its effectiveness.
Deflection of the tailplane does not mean it is useful in providing pitch moment, just as flapping your arms wildly doesn't enable you to fly.
mean theya re not trimming so what is that? of course you need to claim the tailplane lost 100% ability but the canard does not and you do it avoiding the part you do not like but quoting song
No where did I claim the tailplane lost 100% ability. Such a statement is your own invention that you argue against. Thus, this is another example of your
fallacy. All I have stated is that tailplane loses effectiveness, how it is a fact pointed out by many papers, and how it is in agreement with Dr. Song's paper.
As to canards, they have no problem at high AoA. As pointed out by
which you cited, the canard maintain zero AoA and remains an effective control surface even when the aircraft has large AoA:
In piloted supernormal flight of the aircraft of the present invention, the wing of an aircraft, such as a superagile tactical fighter, is either partially or completely stalled, while the longitudinal control surfaces, such as in a rotatable canard arrangement, are deflected to approximately the same magnitude, but of opposite sign, as the angle of attack of the aircraft, so that the canard arrangement remains effective to control the aircraft through large ranges of angles of attack, pitch,and flight path. Such angles may vary from descending flight to deep stall, i.e. -45.degree., to ascending flight in vertical climb, i.e. +90.degree..
This is the same idea presented in Dr. Song's paper.
hahaha when in reality the article says
canard deflection (delta_c) influences the angle of attack in the below-stall range, see Fig-10, but does not influence in the post stall range.......
So to avoid that you quote Song trying to imply the author said canards do work but tailplanes do not
this shows you are just the true fallacy maker since the author at no moment says the canard works
Actually, the authors of the
says tailplane loses effectiveness at high AoA;
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
Tail surfaces losses its effectiveness at high AoA means they cannot provide the necessary pitch moment; that's the reality. Pointing that out with no distortion is not a fallacy, but an act of pointing at facts to debunk your b.s. Also because the paper says tailplane loses effectiveness, it is in agreement with Dr. Song's paper regarding saturation of tailplane at high AoA, hence showing no disagreement with Dr. Song's assertion that canard is superior to tailplane at high AoA.
Just because you are employing fallacies, that doesn't mean others behave in the same way.
your own personal flaws on to others.
Niether the american papers say the canards are better since they say
AFT-TAIL VS CANARD
CONCLUSIONS
* WITH ACTIVE CONTROLS THE COMBATS MISSION PERFORMANCE ARE
COMPARABLE
* THE CANARD CONFIGURATION DOES NOT HAVE ANY FUNDAMENTAL COMPARISON
ADVANTAGES OVER THE AFT-TAIL AIRCRAFT
or the that the aircraft lost total control since
usually does not equal always
Neither do the papers say that canards are worse at high AoA. The papers also do not say tailplane is more effective at high AoA. What we do have are papers that say tailplane is ineffective at high AoA. The
:
A concentration of characteristic curves C[sub]m[/sub] for the tailplane setting angle φ[sub]t[/sub] being varied at post-critical AoA (i.e. very low sensitivity of pitch moment with respect to the tailplane setting angle) reflects the loss of effectiveness of a horizontal tail at higher AoA.
The
says:
It can be explained by loosing of effectiveness of control surfaces... In the range of AoA up to 35[SUP]o[/SUP] the normal increases approximately linearly, then stabilises and practically the tail surface losses its effectiveness.
Then we have a
which was also quoted by you saying canard remains effective to control the aircraft at high AoA:
In piloted supernormal flight of the aircraft of the present invention, the wing of an aircraft, such as a superagile tactical fighter, is either partially or completely stalled, while the longitudinal control surfaces, such as in a rotatable canard arrangement, are deflected to approximately the same magnitude, but of opposite sign, as the angle of attack of the aircraft, so that the canard arrangement remains effective to control the aircraft through large ranges of angles of attack, pitch,and flight path. Such angles may vary from descending flight to deep stall, i.e. -45.degree., to ascending flight in vertical climb, i.e. +90.degree..
Finally, we have Dr. Song's paper that says tailplane saturates and is inferior to canard in providing pitch moment at high AoA:
Control surfaces placed in front of the center of mass, like the canards, are negative load control surfaces. Since the main wing's ability to generate lift tends to saturate under high AOA conditions, the positive load control surfaces' pitch down control capabilities tend to saturate under high AOA as well. Therefore it will be wise to employ negative load control surfaces for pitch down control under high AOA conditions. Figure 7 compares the pitch down control capabilities of the canards and horizontal stabilizers. From the high AOA pitch down control stand point, it will be wise to use canards on the future fighter.
All the papers are in agreement with one another.
So you hang on a lie and misquoting by saying tailplanes can not ever being use something that is a lie since Usally means sometimes most of times but it does not mean always and here it can be talking about the F-15 or F-18 and to prove it see
Such is a
of your own attributes (lying and misquoting) on others. Also, no where have I ever said that "tailplanes can not ever be used". Your claim otherwise is a fallacy known as
and is an example of a lie.
Tailplane loses effectiveness at high AoA. This is applicable to all aircraft. For example,
and is not talking about the F-15 or F-18. In the paper, the authors stated that control surfaces lose effectiveness and that tailplane loses effectiveness:
It can be explained by loosing of effectiveness of control surfaces... In the range of AoA up to 35[SUP]o[/SUP] the normal increases approximately linearly, then stabilises and practically the tail surface losses its effectiveness.
There is no ambiguity there. Tailplane losing effectiveness at high AoA means that the control surface cannot be used to provide necessary pitch-down moment at that situation. Hence, canard is superior to tailplane at high AoA as explained by Dr. Song:
Control surfaces placed in front of the center of mass, like the canards, are negative load control surfaces. Since the main wing's ability to generate lift tends to saturate under high AOA conditions, the positive load control surfaces' pitch down control capabilities tend to saturate under high AOA as well. Therefore it will be wise to employ negative load control surfaces for pitch down control under high AOA conditions. Figure 7 compares the pitch down control capabilities of the canards and horizontal stabilizers. From the high AOA pitch down control stand point, it will be wise to use canards on the future fighter.
the post-stall region provided that several criteria are met:
1. The aircraft has enough thrust to overcome the huge drag increase.
2. The aircraft has controls that will not be rendered ineffective by separated flow over the wings and tail.
from which you have obtained the above bullet points is referring to thrust-vectoring when it says "controls that will not be rendered ineffective by separated flow over the wings and tail". It is not referring to tailplane and does not support your pseudo-aerodynamic theories that tailplane can be used in control at high AoA.
From the very paragraph which follows that bullet point:
Hence the reason that the post-stall region has only been a fairly recent area of study: T/W ratios needed to increase, C[sub]L[sub]max[/sub][/sub] values needed to increase, and non-aerodynamic controls (such as TV) had to be developed before an aircraft would be capable of controlled flight in this very adverse aerodynamic region.
The author's intention is clear.
So your misquoting of the article does not consider that the article says canard do not work you shot your self in your foot and other articles say tailplanes are deflected
If you are referring to the
, it never said canard does not work at all. Quite the opposite, on one page the author mentions that canard is more conductive to high AoA maneuvering than tailplane:
AOA range expanded by 50°, almost twice the T/W ratio at altitude, smaller moments of inertia, and control surfaces more conducive to high AOA maneuvering (i.e. canards vs. a stabilator).
So, was the author shooting himself/herself in the foot. Quite clearly not. The most plausible explanation left is that you are attempting to distort their statements because you are desperately trying to show that your belief of tailplane being effective at high AoA is correct.
In any case, canard is one of those controls that "will not be rendered ineffective by separated flow over the wings and tail", since canard is not linked to the wing and is not part of the tail. In addition, the canard can be orientated to maintain low AoA at all times, as explained in this
:
In piloted supernormal flight of the aircraft of the present invention, the wing of an aircraft, such as a superagile tactical fighter, is either partially or completely stalled, while the longitudinal control surfaces, such as in a rotatable canard arrangement, are deflected to approximately the same magnitude, but of opposite sign, as the angle of attack of the aircraft, so that the canard arrangement remains effective to control the aircraft through large ranges of angles of attack, pitch,and flight path. Such angles may vary from descending flight to deep stall, i.e. -45.degree., to ascending flight in vertical climb, i.e. +90.degree..
There is no contradiction among the papers.
