Su-57 novi ruski lovac

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Citat:
Now, let us take a close look at the Russian PAK FA program. The PAK FA already comes with a forward looking large nose mounted I-band Active Electronic Scanned Array (AESA) radar, smaller, side looking I-band AESA radars, and wing mounted C/D-band AESA radars. In addition, it uses multi-spectral IRST both in the front and back. Going by the prototype it seems that extreme manoeuvrability has been given precedence over all aspects of stealth, so the PAK FA may not carry out the deep penetration role of the F-22. It is understood that the PAK FA has been designed from the onset to detect the F-22 or similar stealth aircrafts from a long distance using its IRST and then destroy these aircrafts in a Within Visual Range conflict.Obviously, designing the avionic suite of the PAK FA (also the Sukhoi/HAL FGFA for India) is not going to be easy for Sukhoi. The provision of high capacity avionic cooling is essential, to avoid producing infrared hotspots. Likewise, the need for wideband, yet very low RCS radio-frequency apertures for the use of both passive and active sensors and aircraft datalink/network terminal transceivers. Unlike the Lockheed Martin F-22, which uses conventional stealth technology for signature reduction, Sukhoi favored another innovative approach – 85 percent of the surface of PAK FA is covered with unique coating made of nano-particle materials that decrease the visibility of the plane. (In addition, this coating is also said to offer extra benefit in drag reduction).

Proper stealth needs to be a factor from the very start of the design stage because every aspect of the design will influence the final radar cross section. There are two aspects that are important with stealth and they are shaping and materials absorption. Shaping means designing the reflecting surface to redirect radar waves coming from any direction in any direction other than the direction the energy came from. Materials absorption means materials that absorb radio waves.

Having a composite radar invisible skin is of limited value. They are currently used in the dielectric nose radome that covers the nose-mounted radar, therefore being transparent to radar (otherwise the radar inside them would not work through them). Making the outer skin of a plane out of that material to achieve low observability would just make the insides of the plane visible to the radar and all that external shaping to redirect radar so that it doesn’t return to the radar antenna would be completely wasted. Given the less demanding Russian requirements for low observability, there is no reason for the PAK FA to use the same range of complex and expensive RCS reduction designs and techniques used in the F-22 or other stealth aircraft.

Citat:The PAK FA will not be some miracle plane, particularly as the two-seater variant for India has severely affected the original Sukhoi Design, but it potentially should outperform most Euro canards and potentially cope better against the MBDA Future Medium Range Air-to-Air Missile (FMRAAM) Meteor because with its IR sensors the PAK FA should be able to detect the Meteor at long range and thus take early avoidance manoeuvres. Even when a Meteor missile turns on its radar scanner, its reduced detection range means the PAK FA pilot need never let it get close enough to detect his aircraft (assuming the Rafael or Typhoon or F-22 or F-35 even detects him in the first place to launch).

http://defense-update.com/20120502_beyond-visual-r.....-asia.html

Malo mi klimav onaj prvi bold o IRST, preterase ga.

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^

Sto li fino sastavi text(cini mi se da rec aircraft ne zahteva nastavak `s` za odredjivanje mnozine ) .U pravu si ima tu propagande i to poprilicno .

Naduvavaju sve lovce pa i PAK-FA .Jedva cekam da i on dodje u tu fazu kada cemo moci da ga poredimo sa F-22 pa i sa Su-27 sto da ne kao ovih dana sto se cini na temi F-22 .Ovako do te faze je sve rekla -kazala cini mi se .

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acatomic ::Futurama ::

Ok evo clanka gde je to nedvosmisleno receno:
http://www.f-22raptor.com/st_fa22tricks.php



Imaš li koji drugi? Ovaj je sa "F-22 fan-site" i nemam nešto poverenja u njega.

Sajtove koji se doticu ove teme nije bas lako naci ali sam nasao jednu knjigu.
Stealth Warplanes by Dough Richardson
na strani 38 se navodi:

Citat:
COCKPITS
One of the most troublesome cavities on an aircraft is the
cockpit. Virtually as transparent to radar energy as it is to light, the
canopy or windshield allows radar energy access to the
cluttered and radar-reflective cockpit interior. The pilot's head
and helmet, the ejection seat and all the various controls and displays
in the cockpit all contribute a major share to the signature of
the aircraft. One way of preventing this is to
use an external shape for the canopy -which conforms to good
low RCS design rules, then to metalise it with a coating which
will have minimal effect of visibility, but will be "seen" by the
radar as being an electrically conductive surface rather than a
transparency - virtually an extension of the aircraft's skin.
Such coatings must pass at least 85 per cent of the visible energy
and reflect virtually all of the radar energy. The techniques for
doing this are well established. A thin layer of gold on the canopy
transparency of the EA-6B Prowler protects the crew from the
powerful signal emitted by the aircraft's jammers. Indium-tin is
another possible canopy coating, and is reported to allow 98 per
cent transmission of visible light. For canopy-plating to be
effective, the conductive film on the transparency must be
electrically continuous with the fuselage. This implies the use of
conductive seals such as the inflatable fabric-reinforced
silicone rubber seals used on the Saab JAS-39 Gripen. Canopy
profile should also be kept low in order to minimise scattering at
the fuselage/canopy junction.


Dakle ako napravis prostu metalizaciju poklopca kabine koja je cist dielektrik (neprovodna) imaces prakticno 100% refleksiju radarskog zracenja. U tom slucaju ne moze biti nikakve znacajne apsorpcije. Tako kazu Maksvelove jednacine.

Medjutim, ako citas dalje:

Citat:
CIRCUIT ANALOGUE
Another type of RAM can be created by replacing the
resistive sheet used in Salisbury or Jaumann
absorbers with one on which conductive material is
arranged in geometric patterns such as thin strips,
grids, crosses or more complex shapes. The result is
known as a Circuit Analogue (CA) absorber. The material
offers a higher performance within a given volume than
simpler types of absorber but must be custom-designed for
each application, a task normally handled by a
powerful computer. CA absorber technology is
probably the principle behind one new method of producing
stealthy canopies. The easiest way of creating a canopy for a
stealth aircraft was mentioned earlier - application of a thin
film of gold or indium-tin to the transparent material. This
conducting film keeps the radar energy out of the
cockpit but will tend to reflect it. A more recent technique
involves making the entire transparency absorb radar
energy. This is done by embedding within it a
network of thin wires cut to dipole (half-wavelength) size.
When combined with an inner conductive layer, this
treatment probably turns the entire transparency into a CA
absorber.


Vidi se da je moguce odredjenim trikom postici apsorpciju i na providnim povrsinama (u optickom delu spektra). Po nekim radovima koje sam nasao iz te oblasti :
http://lup.lub.lu.se/luur/download?func=downloadFi.....Id=1581319
radi se uglavnom o apsorberima u okviru jednog opsega (recimo 8-12GHz - X opseg) i slabljenja se krecu oko 20dB tj. 100 puta. Van tog opsega su neefikasni tj. opet imas refleksiju.
Moguce je da je na kabini T-50 primenjen upravo ovakav metod.

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Samo sto je tekst malo... Zavrsili smo sve u vezi naoruzanja za njega samo

A number of weapons systems for future fifth-generation fighter PAK FA is in a high degree of readiness, although it is necessary to resolve "a number of difficult issues," said chief executive officer "Tactical Missiles," Boris Obnosov.

http://sdelanounas.ru/blogs/18093/

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Fourth T-50 Stealth Fighter to Fly This Year

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Петр Бутовский о ПАК-ФА

http://sdelanounas.ru/blogs/18544/

Na T-50-3 je ugradjen radar, na neki nacin jer ima samo prednju antenu. Opet potvrdjuje da ne lete do sada zbog otkrivenog problema sa konstrukcijom( nije prosao trestove sa vecim G silama ) koja mora da se ojaca i da su za T-50-1 zbog toga zavrsena letna testiranja ili bar jedan deo njih. Prica o KS-101 na T-50-3, poredjenja sa Raptorom u vezi usisnika, izduva, vertikalca, prica o motoru za PAK FA "Product 30"

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Sa keypublishig-a konačno

Berkut ::T-50-3 has started taxi tests. Thanks for the newsbit to Flateric.

http://forum.keypublishing.co.uk/showthread.php?p=1900966#post1900966

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Zukovski 2012

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^^^

Treci?