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IRANIAN Concept stealth fighter _ ZXX HOUND

Nice job Soheil baradar. It takes some brain, imagination and aspiration to come up with your own design. You should be proud of your self. :tup:

By the way, where is Soheil. I have not seen him lurking around lately? :azn:
 
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He means the round shape as a deviation from the all straight edges which should be as much designed to disperse radar beams. Round shapes returns it back to the source better.
Wrong. I can see a lot of misconceptions about radar detection and low radar observability already. This is what happens when people are fixated on a colorful drawing rather than on basic science.
 
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Wrong. I can see a lot of misconceptions about radar detection and low radar observability already. This is what happens when people are fixated on a colorful drawing rather than on basic science.

it is what i feel when i watch American Films :drag:
 
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Designer : Soheil Esmail zadeh

Name : ZXX B HOUND

So}{eil copyright 2012

MADE IN IRAN

Technique : CGI


soheil_esy@yahoo.com

(Modified version)

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Wrong. I can see a lot of misconceptions about radar detection and low radar observability already. This is what happens when people are fixated on a colorful drawing rather than on basic science.

So, the lack of curves on the F-22 and F-35 is based on colorful drawings?

Basic science is: angular curves dissipate most of the radar beams in accordance to how the airplane is positioned at the time of the impact of radar emissions.
Round curves always return some emission no matter how the plane is positioned in regards to the emission source.
 
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So, the lack of curves on the F-22 and F-35 is based on colorful drawings?

Basic science is: angular curves dissipate most of the radar beams in accordance to how the airplane is positioned at the time of the impact of radar emissions.
Round curves always return some emission no matter how the plane is positioned in regards to the emission source.
But at what intensity level?

radar_plate_sphere_resp.jpg


There is no such thing as 'Round curves'. It is a redundancy. Angled faceting was the F-117. Curvatures are what is incorporated into the current generation. So while it is true that a curvature will always reflect a small amount of 'specular' energy back to source (seeker) direction, the intensity level is sufficiently far below certain threshold acceptable for 'stealth'.
 
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The text you posted just proves my point. Circular in most cases returns more emissions from the source-ie there are more gains to be made with "thought out" angles then curves.
I believe it is only a technical problem from there on. Sensors on board the aircraft see from where the radar waves are coming from and a low radar observable mode flight controls go on, so that the airplane is turned with angular edges towards the source for as much time as possible.

Also on the built with curves-there are very little curves on the F-22, in any case much less then on F-35 which also according to internet rumours(wiki) has a higher RCS.

In regards to the intensity level returned and the usage of some curves on modern stealth airplanes. i have a theory a lot of that is due to advances in coating, materials, more advanced flight controls, ECM, active cancellation etc. and not so much because it is a good shape. Its just that the minuses it inherently brings are minimized or eliminated all together by the factors above.
 
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The text you posted just proves my point. Circular in most cases returns more emissions from the source-ie there are more gains to be made with "thought out" angles then curves.
No, it does not. Am willing to bet you did not even read it.

This means that the flat plate would produce a response some 12000 times greater than the sphere or, alternately, a sphere having some 12000 times the projected area of the plate would have to be place at the same range as the plate to produce the same response. It is interesting to note that any slight change in the aspect of the plate will result in a massive drop in the response, whereas no change will occur if the sphere is reorientated.
The problem here is that you, like most people, assume that a response is inherently a negative thing when in radar detection, most results are not concluded until they are held against a threshold.

The 'angled faceting' technique is essentially a 2D approach to radiation control. The idea was to:

- Analyze aerodynamic efficiency,

- If at any point where said aerodynamic demand produces an increase in radiation level, we will attempt via 'angled facets' to control the behavior of radiation pattern and direction.

- If said attempt conflict with aerodynamic demand to the point of an increased risk of departure from controlled flight, the aerodynamic demand must take precedent.

In other words, aerodynamic demands trumps all considerations.

The result is this comparison...

f-117_f-22.jpg


What you called 'thought out angles' did not give the F-117 the maneuverability pilots wanted, although it was more maneuverable than the public believed. With the introduction of curvatures, thanks to supercomputers, we have a 3D approach to radiation control via surface wave behaviors. In other words, the 'angled faceting' approach focused only on impact and reflection while curvatures introduces surface wave behaviors as well as impact and reflection.

The tiny amount of specular reflection that a curvature produces, which is 12000 times less than a full-frontal plate, is comparable to that of an angled plate. It is only when the plate is completely 'edge-on' to the radar is when said plate produces less radiation. Even so, the edge of that plate will reflect some amount back to source (seeker) direction. This understanding give us the B-2, F-22, and F-35 with all their curves.

I believe it is only a technical problem from there on. Sensors on board the aircraft see from where the radar waves are coming from and a low radar observable mode flight controls go on, so that the airplane is turned with angular edges towards the source for as much time as possible.
You are partially correct in that an aircraft is a complex body and no aircraft can be so uniform on any side. To date, the only aircrafts that are capable of such threat analysis are the B-2, F-22, and F-35.

Also on the built with curves-there are very little curves on the F-22,...
You must be joking. See image comparison above.

...in any case much less then on F-35 which also according to internet rumours(wiki) has a higher RCS.
But if the F-35's RCS is below the threshold that is rejected by 99% of the world's radars, who cares? We do not. This is a weak argument/criticism against the F-35. EVERYTHING is dependent upon a threshold, in this case it is the 'clutter rejection threshold'. Our 'stealth' aircrafts are designed to have themselves inserted into this threshold automatically by the seeking radar.

In regards to the intensity level returned and the usage of some curves on modern stealth airplanes. i have a theory a lot of that is due to advances in coating, materials, more advanced flight controls, ECM, active cancellation etc. and not so much because it is a good shape. Its just that the minuses it inherently brings are minimized or eliminated all together by the factors above.
For the F-22 and F-35, absorber use is more than 60% less than the F-117. I will not say exactly how much more, but the 60% figure will suffice. You are free to believe any other figure you wish. Flight controls have nothing to do with a curvature's radiation response. ECM is not a good thing for 'stealth' because an ECM transmission is an active measure. Active cancellation is not yet feasible, but when it is , we will be the first to deploy, probably without anyone's knowledge. :lol:
 
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No, it does not. Am willing to bet you did not even read it.

Ofcourse i read it. Problem is, you want to tell me spherical aircraft are best, but im not buying it.
The people who build these planes also disagree with you. I mean if you were correct and sphere is best under all regimes and angles of flight , there would be tear or sphere shaped aircraft right now.

The problem here is that you, like most people, assume that a response is inherently a negative thing when in radar detection, most results are not concluded until they are held against a threshold.
The 'angled faceting' technique is essentially a 2D approach to radiation control. The idea was to:
- Analyze aerodynamic efficiency,
If at any point where said aerodynamic demand produces an increase in radiation level, we will attempt via 'angled facets' to control the behavior of radiation pattern and direction.
- If said attempt conflict with aerodynamic demand to the point of an increased risk of departure from controlled flight, the aerodynamic demand must take precedent.
In other words, aerodynamic demands trumps all considerations.
The result is this comparison...

What you called 'thought out angles' did not give the F-117 the maneuverability pilots wanted, although it was more maneuverable than the public believed. With the introduction of curvatures, thanks to supercomputers, we have a 3D approach to radiation control via surface wave behaviors. In other words, the 'angled faceting' approach focused only on impact and reflection while curvatures introduces surface wave behaviors as well as impact and reflection.

I meant a comparison of the curves with former generation of aircraft. And i was refering to thought out angles on the F-22 and F-35.
You are a bit selective no? You answer only the most convenient version. Now do tell me how do the thought out angles hamper maneuverability on the F-22 for example.
Undoubtedly there are curves on the newer generation of planes but they are all pretty much uniformly built with angled surfaces. Thats why the whole bottom side of the F-22 is angled-to disperse as much as possible under ALL flight regimes.
I would go on further more to speculate that the F-22 has more curves (numerically) if you are looking at it from the side view plane as opposed to the top view, because top view presents a larger surface for the signals to return.
A tradeoff-more curves that improve handling etc on the side that is the least vulnerable to emission returns and less on the side that returns more.

The tiny amount of specular reflection that a curvature produces, which is 12000 times less than a full-frontal plate, is comparable to that of an angled plate. It is only when the plate is completely 'edge-on' to the radar is when said plate produces less radiation. Even so, the edge of that plate will reflect some amount back to source (seeker) direction. This understanding give us the B-2, F-22, and F-35 with all their curves.

Yes, and that's why the leading edges of these aircraft are all angled. That's why there are less curves on them then on the older planes.
Point is, because spherical shapes return energy in all directions, at some point (flight profile) it will become counterproductive and will have to be replaced with angles which in turn have there own minuses but with thought out processes (threat analysis-and turning the aircraft with its best side at that point to the source) you minimize those minuses.
Again, it is a trade-off, a compromise, that progress in supercomputing and understanding of wave behaviour made possible.


But if the F-35's RCS is below the threshold that is rejected by 99% of the world's radars, who cares? We do not. This is a weak argument/criticism against the F-35. EVERYTHING is dependent upon a threshold, in this case it is the 'clutter rejection threshold'. Our 'stealth' aircrafts are designed to have themselves inserted into this threshold automatically by the seeking radar.


According to information available on the internet the F-35 is only very stealthy to the types of radars that work in a particular band, while the F-22 is stealthy to radars that work in all bands.

For the F-22 and F-35, absorber use is more than 60% less than the F-117. I will not say exactly how much more, but the 60% figure will suffice. You are free to believe any other figure you wish. Flight controls have nothing to do with a curvature's radiation response. ECM is not a good thing for 'stealth' because an ECM transmission is an active measure. Active cancellation is not yet feasible, but when it is , we will be the first to deploy, probably without anyone's knowledge. :lol:

Some credible link please for the coatings statement. Thanks

Also i mentioned flight controls in the context of making the aircraft turn in such a way to limit RCS,active cancellation is employed on the French Rafale, i wouldnt speculate on what it actually does and how but it is there and marketed as active cancellation SPECTRA.
I mentioned all that in the broader picture of being less visible/untargetable.
 
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Ofcourse i read it. Problem is, you want to tell me spherical aircraft are best, but im not buying it.
The people who build these planes also disagree with you. I mean if you were correct and sphere is best under all regimes and angles of flight , there would be tear or sphere shaped aircraft right now.
A sphere is obviously out of the question. But an 'ogive' is real and for the F-22, when view from the side, its shape is approximate to that of an ogive.

Solutions for Aerospace & Defense | Antenna Measurement Solutions
Our pylons offer a precise ogive surface, minimizing radar returns while providing high load capacity.
In radar ranges, open fields or internal, the supporting structures such as pylons large enough to hold full scale models or small enough to hold a variety of objects must be eliminated from measurement. The cylinder is not used because of the potentiality of the creeping wave effect. So an ogival pylon is the next best thing. The same concept applies to shaping a complex body for RCS control. So no, I doubt that you actually read the excerpt.

I meant a comparison of the curves with former generation of aircraft. And i was refering to thought out angles on the F-22 and F-35.
You are a bit selective no? You answer only the most convenient version. Now do tell me how do the thought out angles hamper maneuverability on the F-22 for example.
Easy...Aerodynamic demands. Air flow across a surface will be disturbed with angled facets and will increase the risk of departure from controlled flight. That is why the technique is not applied to the wing's surface. However, on the fuselage, we can apply the technique and that is evident with the F-117. For radar signals, the aircraft would not crash if the signals radiate off the surface but it would make the aircraft visible in the EM spectrum. So when we were able to use supercomputers to model, predict, and measure surface wave behaviors induced by curvatures, we have the best compromise of both demands: Aerodynamics and RCS control.

Undoubtedly there are curves on the newer generation of planes but they are all pretty much uniformly built with angled surfaces. Thats why the whole bottom side of the F-22 is angled-to disperse as much as possible under ALL flight regimes.
I would go on further more to speculate that the F-22 has more curves (numerically) if you are looking at it from the side view plane as opposed to the top view, because top view presents a larger surface for the signals to return.
A tradeoff-more curves that improve handling etc on the side that is the least vulnerable to emission returns and less on the side that returns more.
Sorry...But you are still way off base.

radar_reflect.jpg


The above is an illustration of: the plate, the tip, the Keller cone, the corner, the edge, and the surface waves. These behaviors exist in some measure even on the F-22. The issue is to what level that will breach a certain threshold and how much of them will return to source (seeker) direction. Curvatures induces large quantities of surface wave behaviors and the less surface discontinuities there are, the longer the signal will stay on the surface, the less 'leaky' waves into free space, and finally whatever remain will bleed off on the shadow region -- away from the seeking radar.

Yes, and that's why the leading edges of these aircraft are all angled. That's why there are less curves on them then on the older planes.
You might want to review your understanding of the words 'angled' and 'curves' in proper contexts. We are talking more about surface and less about structures. The SWEEP angle of the wing for aerodynamic demands is not the same as how a surface is 'angled' to effect RCS control. So specular reflections and Keller cone diffraction signals from the leading edges can be minimized with absorber. However, if the SURFACE of the wing is not free of discontinuities...

radar_groove_wave_reflect.jpg


There will be even more diffracted signals. Ben Rich recalled...

Amazon.com: Skunk Works: A Personal Memoir of My Years of Lockheed (9780316743006): Ben R. Rich, Leo Janos: Books
Chapter 3 The Silver Bullet

I was feeling particularly skittish on that score because a few weeks before the contract negotiations began, I received an urgent call from Keith Beswick, head of our flight test operation out at the secret base.

"Ben," he exclaimed, "we've lost our stealth". He explained that Ken Dyson had flown that morning in Have Blue against the radar range and was lit up like a goddamn Christmas tree. "They saw him coming from fifty miles."

Actually, Keith and I both figured out what the problem was. Those stealth airplanes demanded absolutely smooth surfaces to remain invisible. That meant intensive preflight preparations in which special radar-absorbent materials were filled in around all the access panels and doors. This material came in sheets like linoleum and had to be perfectly cut to fit. About an hour after the first phone call, Keith phoned again. Problem solved. The heads of three screws were not quite tight and extended above the surface by less than an eighth of an inch. On radar they appeared as big as a barn door!
So three screws created sufficient quantity of diffraction signals that it revealed the F-117 from 50 miles away.

So once again, the SWEEP ANGLE of the wings is about structure and does not have the same context as the 'angled' faceting technique, which is about surface. Both will reflect but under different behaviors.

Point is, because spherical shapes return energy in all directions,...
Not 'spherical' but 'curvatures'.

...at some point (flight profile) it will become counterproductive and will have to be replaced with angles which in turn have there own minuses but with thought out processes (threat analysis-and turning the aircraft with its best side at that point to the source) you minimize those minuses.
Again, it is a trade-off, a compromise.
On a complex body it is inevitable that some aspect angles of the aircraft will reflect overall greater than others. Curvatures reduces this while continue to accommodate aerodynamic demands.

According to information available on the internet the F-35 is only very stealthy to the types of radars that work in a particular band, while the F-22 is stealthy to radars that work in all bands.
I see you felled for that, eh? :lol:

News for you, different bands are good for certain tasks.

freqs_applic.jpg


If there are any differences in detection distances between the F-22 and F-35, they are tactically minimal.

Some credible link please for the coatings statement. Thanks
Try this...

F-22 Raptor Factsheet :: Air-Attack.com
The F/A-22 is constructed of titanium alloys (39% by weight); composites (24%); aircraft aluminum alloy (16%); and thermoplastics (1%). Advanced titanium welding techniques and composite fabrication are used in the aircraft's construction. "Radar absorbent material (RAM)" is used in critical locations to reduce the aircraft's radar signature, and the aircraft's contours are intended to make it less conspicuous to radar.
Does not say all over. Only on 'critical locations'. Do not expect me to say anymore than what I have given you.

Also i mentioned flight controls in the context of making the aircraft turn in such a way to limit RCS,...
Only we have that for now. But the tie-in to the FLCS is tenuous at best. Usually when avionics specialists speaks of the FLCS, we prefer to leave it as a standalone entity.

...active cancellation is employed on the French Rafale, i wouldnt speculate on what it actually does and how but it is there and marketed as active cancellation SPECTRA.
I have opined on the SPECTRA here before. Look it up. The system is not 'active cancellation'. It is ECM. Active cancellation mean to negate at the surface or at the interior.

I mentioned all that in the broader picture of being stealthy/less visible/untargetable but you tookit and belittled it a bit.
No, I put it in their proper contexts.
 
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Ok, so in a nutshell, why is the F-22 when viewed from top view (the side with most returns as according to surface area) lacking curves?
Why doe it have chines instead of LERX?

Lets forget that in previous post you simply dismissed it as "im way off course".
I'm guessing the designers at LM weren't as much off course as you make the seem.

While you are at it also explain why the predominant shape of contemporary fighters deviated from the tubular fuselage to a more geometrically correct shape with angles when viewed from forward and top?

Also the oval shaped argument when looked from the side-the key word is from the side-where there is less return because of less surface area. So, tradeoffs can be made to accomodate both aerodynamics and stealth.

Explain all this without deflecting attention on some "you might want to review your knowledge ofthis and that" or diagrams of ancient fighters that don't reflect reality.
A good example of this would be the corner thingy-on your picture its is set up at a right angle sowhen it bounces off 2 surfaces it returns in the same path-in contrast to the stealth fighter corners which are all tilted so that the signal isn't returned in the same direction.

As for the F-35 being less stealthy, it is a fact widely recognized on various forums-the USAF posted that info. Going on memory alone here but i remember it saying its shape is optimised for radars in SAM installations, fighters and seekers in missiles. S and X bands iirc-so in theory all it would take is make a radar that works in a different band.
Yes it would be inferior to the other (normal) radar in everything but detection of shapes/surfaces which were designed specifically to beat the X, S band radar.

It would be interesting to know out of what composites the F-22 is made and if they have some inherent radar absorbing characteristics that make the use of coatings "obsolete" or moot.
 
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Some of these days, guys from "Lockheed Martin Skunk Works" will contact Soheil and hire him at their plant. He is really busy in his basement.

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The one at front is Melika bringing Soheil's newest creation to PDF.

this pic shows these guys very well!
 
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