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Design characteristics of canard & non canard fighters

Then why they didn't apply the delta wing instead of the convetional one as They use now?.

The deal is that the Russians also use conventional wings in their fighters.

I dunno. The F-16XL was competing against the F-15E for the strike role. F-16XL lost out since it's better to have two engines instead of one for that kinda role.

imagine if the F-16XL was revived powered by the latest F110-GE-132
2-Fightertriebwerke-F110-GE-132.jpg.2420086.jpg


the AN/APG 80 AESA Radar

and loaded with air to ground weapons like Brimestone,SDB I/II, and LJDAM


brimstnb.jpg


1055263010.jpg



900_LJDAM_on_F-16_Close-Up.jpg
 
and severe problems with low-speed, high AoA manuvering (Deltas have a major problem with the airflow separating from the wing at high AoA).

This may be true with mechanical controls but is entirely false with fly by wire systems.
 
This may be true with mechanical controls but is entirely false with fly by wire systems.

Fly-by-wire controls don't improve design efficiency though. They only ensure unstable designs can be flown safely. The inherent problems of the design are still present, such as airflow problems with delta-wing configurations. The Fly-by-wire just ensures the air-frame can actually fly - the inherent instability of modern designs would make them too unsafe.

Pure delta-wings fell out of favour somewhat due to their undesirable characteristics, notably flow separation at high angles of attack (swept wings have similar problems), and high drag at low altitudes. This limited them primarily to high-speed, high-altitude interceptor roles.

Delta wing
 
What is this if you have spare time to explain.

Also this character didn't prevent the Euros from having them on their top fighters.

I dunno. The F-16XL was competing against the F-15E for the strike role. F-16XL lost out since it's better to have two engines instead of one for that kinda role.

imagine if the F-16XL was revived powered by the latest F110-GE-132
2-Fightertriebwerke-F110-GE-132.jpg.2420086.jpg


the AN/APG 80 AESA Radar

and loaded with air to ground weapons like Brimestone,SDB I/II, and LJDAM


brimstnb.jpg


1055263010.jpg



900_LJDAM_on_F-16_Close-Up.jpg
This fighter no doubt best of the best.

if the US didn't go for the F-35 the F16 would be good for another 40 years it's desgin were ahead of it's time and with better electronics it will dominate the skies.

I want to see them in our sky with our flag but uncle sam still undecided.
 
Also this character didn't prevent the Euros from having them on their top fighters.

I'll have to let someone else explain the intricacies of Flow Separators, @SvenSvensonov could do it. But on the Eurofighter, yes, its delta wing configuration does have problems. To compensate for the flow issues associated with the delta design, the Eurofighter, JAS 39 and Rafale all pair their delta wings with canards, which help rectify the airflow issues.

Many modern fighter aircraft, such as the JAS 39 Gripen, the Eurofighter Typhoon and the Dassault Rafale use a combination of canards and a delta wing.

Delta wing

A canard foreplane may be used for various reasons such as lift, (in)stability, trim, flight control, or to modify airflow over the main wing. Design analysis has been divided into two main classes, for the lifting-canard and the control-canard.These classes may follow the close-coupled type or not, and a given design may provide either or both of lift and control.

Canard (aeronautics)

In the case of the Eurofighter, the canards help solve airflow problems with the main wing, they also afford the Eurofighter maneuverability improvements, such as a tight turn radii.

So it's true the the Europeans weren't stopped by the inefficiencies of the delta configuration, they just had to add canards to their designs to compensate for airflow problems.

Each of these aircraft are tailless-delta configurations, each must use canards to correct airflow problems with the main wing.
JAS39Gripen.jpg


Rafales_aboard_USS_Harry_Truman.jpg


1402230.jpg
 
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I'll have to let someone else explain the intricacies of Flow Separators, @SvenSvensonov could do it. But on the Eurofighter, yes, its delta wing configuration does have problems. To compensate for the flow issues associated with the delta design, the Eurofighter, JAS 39 and Rafale all pair their delta wings with canards, which help rectify the airflow issues.

Many modern fighter aircraft, such as the JAS 39 Gripen, the Eurofighter Typhoon and the Dassault Rafale use a combination of canards and a delta wing.

Delta wing

A canard foreplane may be used for various reasons such as lift, (in)stability, trim, flight control, or to modify airflow over the main wing. Design analysis has been divided into two main classes, for the lifting-canard and the control-canard.These classes may follow the close-coupled type or not, and a given design may provide either or both of lift and control.

Canard (aeronautics)

In the case of the Eurofighter, the canards help solve airflow problems with the main wing, they also afford the Eurofighter maneuverability improvements, such as a tight turn radii.

So it's true the the Europeans weren't stopped by the inefficiencies of the delta configuration, they just had to add canards to their designs to compensate for airflow problems.
Thanks I got it now from the pics posted by @SvenSvensonov.

But we still see the M2k using them we didn't hear that this plane crashed do to wings air flow seperator.

Any way it's a nice info we learned today thanks for all of you.
 
^ this is not a 2000 but a Mirage 4000.

The 2000 does not use canard, but something called "aigrettes".
They are used to ensure lateral stability at high alpha.
 
I just found the English translation, it's a "strake".

aigrettes.png


1427839185-deltavortexmirage2000.png
 
Each of these aircraft are tailless-delta configurations, each must use canards to correct airflow problems with the main wing.
That's not entirely correct ma'am or rather, shall I say imprecise.
The Typhie uses its canards for long-moment arm. They do not however contribute to airflow much if at all. Which explains why it has strakes.
The Raffy, yes; the canards mainly modulate airflow for the wings. Then again, they do so with such
efficiency that instead of correcting inherent problems, they end up augmenting the wing functions like
lift and so on to a level past that of many non delta designs. It also has lerx functions in its body wing blend, BTW. So do the Typhie and Gripen.
And in any case, the Falcon is a delta too albeit a tailed one? It really does not matter how you complete
the delta structure by adding tail surfaces, canards or making double delta or ogival as long as it works.

Check this and tell me how popular deltas are :
visual.jpg

The only aircraft that has no delta characteristics is the F-18 and it gets the biggest Lerx ever seen to compensate.
The Lighting II and Raptor have trapezoidal wings, delta with rear sweep mostly for stealth reasons.

Good evening to you, Tay.
 
That's not entirely correct ma'am or rather, shall I say imprecise.
The Typhie uses its canards for long-moment arm. They do not however contribute to airflow much if at all. Which explains why it has strakes.
The Raffy, yes; the canards mainly modulate airflow for the wings. Then again, they do so with such
efficiency that instead of correcting inherent problems, they end up augmenting the wing functions like
lift and so on to a level past that of many non delta designs. It also has lerx functions in its body wing blend, BTW. So do the Typhie and Gripen.
And in any case, the Falcon is a delta too albeit a tailed one? It really does not matter how you complete
the delta structure by adding tail surfaces, canards or making double delta or ogival as long as it works.

Good evening to you, Tay.

And this is why I'm not an aeronautics engineer:p:.

That's not entirely correct ma'am or rather, shall I say imprecise.
The Typhie uses its canards for long-moment arm. They do not however contribute to airflow much if at all. Which explains why it has strakes.
The Raffy, yes; the canards mainly modulate airflow for the wings. Then again, they do so with such
efficiency that instead of correcting inherent problems, they end up augmenting the wing functions like
lift and so on to a level past that of many non delta designs. It also has lerx functions in its body wing blend, BTW. So do the Typhie and Gripen.
And in any case, the Falcon is a delta too albeit a tailed one? It really does not matter how you complete
the delta structure by adding tail surfaces, canards or making double delta or ogival as long as it works.

Check this and tell me how popular deltas are :
View attachment 210012
The only aircraft that has no delta characteristics is the F-18 and it gets the biggest Lerx ever seen to compensate.
The Lighting II and Raptors have trapezoidal wings, delta with rear sweep mostly for stealth reasons.

Good evening to you, Tay.

Isn't it also worth noting that each delta-configuration has different perks and problems? The tailed delta's problems differ from those of the tailless which are different from the cropped design on the F-16.

So saying one is delta and one isn't is a bit difficult, but I agree with the premise and the math behind it, that each aircraft's configuration and use of aids such as canards will differ as their designs differ too.

In any event, I'll let my better half, @SvenSvensonov explain these things from now on, not my area of expertise.
 
I have always been curious to know the machinations behind the minds of designers of fighter jets.
Why do fighter jet designers come up with wildly different designs to essentially do the same job ?

I would like to compare 2 most common wing shapes to better understand why aeroplanes are designed the way they are.


I will start off the thread by enumerating some advantages of both.
Delta Wing
Advantages:
1.Higher Instantaneous Turn Rate(ITR)
2.Better for achieving and maintaining supersonic speeds
3.Higher stall angle
4.More lift.
5.Less wing loading.
6.Stronger than conventional wing, relatively simple and cheaper to manufacture
7.More internal volume for fuel
8.Less stress on the wing, longer life, higher availability and cheaper maintenance.


Conventional Wing:
Advantages:
1.Better Sustained Turn Rate(STR)
2.Better at low speeds.
3.Less air drag

Can anyone care to do a comparative analysis of both, I am sure I have missed many points.

For a comparison. Go here.
Aeronaut: The Mirage III/5/50 Family

Ill post the most relevant excerpts here.

Delta Wing Aerodynamics
by ACdre Retd Kaiser Tufail


Sweep angle of the wing leading edge helps delay drag rise with increase in speed. In a swept wing, the velocity of the airflow normal to the leading edge is reduced by a factor of the cosine of the sweep angle, with a corresponding delay in drag rise. High sweep angles are, however, associated with the problem of wing-tip stalling which results due to the airflow drifting span-wise across the wing, causing the tips to stall before the rest of the wing. The result is usually a violent pitch up followed by a spin. Wing fences and notches are a stop-gap solution as they generate a vortex over the wing which virtually arrests the span-wise airflow.

On a swept wing, the torsional stresses during manoeuvring flight are enormous and indeed, dangerous at high Mach numbers. Greater structural strength can only be obtained by paying a greater weight penalty.

There is one way in which sharp sweep angles can be used without a lot of problems: delta wing. The shape is optimum for high speed flight. The extremely broad chord(average distance between leading and trailing edges) means that a low thickness-to-chord ratio needed for high speed flight can be achieved. The structure can be made rigid, has sufficient volume for fuel and, there are hardly any practical limits to the angle of sweep.

The low aspect ratio (square of the wingspan to wing area) of the delta wing gives excellent supersonic performance by presenting a smaller frontal area to the airflow. At lower speeds, however, the poor lift-drag ratio of the low aspect delta planform demands higher angles of incidence to generate the same amount of lift compared to a conventional wing. This causes greater induced drag resulting in speed bleed-off during manoeuvring flight; it also increases take-off and landing distances. It may be worth noting that the Mirage III/5/50 as well as the double-delta winged Draken, held the dubious distinction of having the lowest (read worst) aspect ratio of any fighter to date ie, 1.94 and 1.8 respectively, but this record has now been surpassed, surprisingly, by the very modern Tejas with a ratio of 1.75!
By its very shape, a delta wing has a large area which tends to give a relatively low wing loading (aircraft weight per unit area of lifting surface ie, the wings). This helps offset its poor sustained turn performance and enables it to turn tightly at low speeds – often below its normal landing speed – especially in descending manoeuvres in which it can trade height for energy.

Woes of Tailless Deltas

To date, only a few tailless delta fighters have been produced besides the Mirage III/5/50. These include the F-102 Delta Dagger, F-106 Delta Dart, J-35 Draken, J-37 Viggen, Mirage 2000 and Tejas.

In a tailless delta, lift augmentation devices like trailing edge flaps cannot be installed for want of space (though in the Viggen, these are cleverly placed on the large fixed canards). Also, upgoing elevons diminish wing lift which needs to be compensated by higher take-off and landing speeds, worsening short-field performance. Many a pilot who ended up in the arrester barrier has ruefully wished for a longer runway when confronted with a take-off emergency.

Two modern tailless delta fighters, the Mirage 2000 and Tejas feature relaxed static stability. A benefit of this design is that it confers an unstable nose-up moment which reduces the pitch-up required for take-off or during manoeuvres; the harm done to wing lift by upgoing elevons is, thus, minimised to a considerable extent. Leading edge flaps/slats on these fighters also add to the total lift when they automatically activate at slow speed, thus allowing lower take-off and landing speeds.

Canards acting as control surfaces work essentially like tailed deltas, except that the ‘tails’ are located at the front. They obviate the need for elevons to change the pitch, hence saving precious main wing lift. Modern delta-winged fighters like Chengdu J-10, Eurofighter, Gripen and Rafale have fully active canard controls.

Some of the older Mirage III/5/50, Cheetah D and Kfir C-II found a partial remedy to their congenital woes through retrofit of small fixed canards, while the Viggen had fixed canards designed from the outset. These canards added to the overall lift in ways similar to the leading edge flaps/slats, except that they remained stuck out even when not needed in high speed flight
 
That's not entirely correct ma'am or rather, shall I say imprecise.
The Typhie uses its canards for long-moment arm. They do not however contribute to airflow much if at all. Which explains why it has strakes.
The Raffy, yes; the canards mainly modulate airflow for the wings. Then again, they do so with such
efficiency that instead of correcting inherent problems, they end up augmenting the wing functions like
lift and so on to a level past that of many non delta designs. It also has lerx functions in its body wing blend, BTW. So do the Typhie and Gripen.
And in any case, the Falcon is a delta too albeit a tailed one? It really does not matter how you complete
the delta structure by adding tail surfaces, canards or making double delta or ogival as long as it works.

Check this and tell me how popular deltas are :
View attachment 210012
The only aircraft that has no delta characteristics is the F-18 and it gets the biggest Lerx ever seen to compensate.
The Lighting II and Raptor have trapezoidal wings, delta with rear sweep mostly for stealth reasons.

Good evening to you, Tay.

So do all aeronautical engineers agree nowadays that delta wing is preferable over conventional wing ?
Especially for a point defence interceptor ?
 
So do all aeronautical engineers agree nowadays that delta wing is preferable over conventional wing ?
Especially for a point defence interceptor ?
Well, yes and no, Topgun. Slower planes or planes without FBW will never fully benefit from being deltas.
But as you move near or above Mach, swept wings is a minimum, say for heavier aircrafts as bombers.
Oscar's reference piece above is for pure or tailless deltas except that before F-16 and M-2000 as said,
FBW was absent but once you incorporate it and one of the many patches, horizontal tail surfaces, canards
or to a lesser degree thrust vectoring, yes, pretty much.
What is a flying wing body but a mono piece delta for instance? It usually has jagged cutoffs on the trailing
edge to allow for more/wider elevons, mixing the characteristics of swept and delta wings but it remains very
much a triangle once you factor in the central body.* So that tomorrow?

Check this view of 4th vs 5th gen Russian design :
russian-jets.jpg
Moving from swept wing to double delta, wouldn't you say.

And if you look at the so-called 6th gen projects from the US, m'well :
Picture_1.JPG boeing-6th-generation-concept-2.jpg 1*uZKtLfEJEBwMfABv5kohiQ.jpeg

8-) Tay.


* The Northrop YB-49 was a rare case of a more normal wing without fuselage.
 

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