asprinzl wrote:Its stealth. It is illusive. Its MAYA.
Uh no - Reminds me of Ammagedon!
disha wrote:asprinzl wrote:Its stealth. It is illusive. Its MAYA.
Uh no - Reminds me of Ammagedon!
A week past when the PAK·FA flew, it is the time to summarize some information we collected before till the some of huge pix showing PAK·FA released nowadays.
While the PAK·FA unveiled, it still surprised most of aircraft fans, although seemed they saw it somewhere or somewhen. Why, because the PAK·FA does have some advantages hidden behind the attractions from its appearance.
The first impressive character is its CARET inlet.
CARET inlet was not innovatively used by PAK·FA but S.H.E/F, nevertheless, the basic principle of CARET inlet is wave-ride, Russian used it better than American on PAK·FA, that's why we saw they transversely set the rectangular section of CARET inlet. Review: the longer the horizontal wedged edge, the more lift will be.
Second, movable LERX upon the CARET inlet.
This is the first time we saw a movable LERX was used on a true jetfighter, we remember Indian HAL LCA Tejas was planned it but that was merely a plan.
Is this only a movable LERX? I think it also is a vortex aileron, not a flap, it is capable to up-deflect, so it contains canard function too. We say it is a movable LERX because the angle of swept is really large enough to be a LERX. A large angle of swept edge cause vortex roll from down site to the up surface, however, when being slight AoA, this swept angle is too large to keep the pressure under the LERX so give a movable leading edge down deflect for works.
Then if you watch carefully, the LERX was up deflecting when PAK·FA tends to take-off, so the effect of this period factually is a canard alike.
Moreover, the movable LERX is a easy way to regulate the swept angle of shock wave produced by edge of CARET inlet whereas F-22 made it bypass door which was a hard method.
Thirdly, all-moving dorsal fins.
The earliest all-moving vertical tail we can remember was A-5 Vigilant used. The most strongest memory the A-5 gave me was wide-side setting engine nacelle, which also brought a commodious weapon bay to the A-5 Vigilant. Following the A-5 was F-14，the favorable jetfighter to the most military fans. The Tomcat set duel-fin. Now it is PAK·FA turn, that duel-fin is not enough to control such wide airframe, plus, too many tough maneuver are waiting for it to do, then we saw a couple of all-moving vertical tail with considerably small area for reducing weight.
Compare to the ATF from YF-22 to F-22's junk-like tail fin, this all-moving vertical-wing gives PAK·FA amount of advantages: reducing weigh; reducing RCS, more stability in High-maneuver, more controllability for yaw and spin.
Fourthly, omnidirectionanl vectoring thrust.
The nozzle F-22 like is worked for doable TVC at that time because airtight of movable workpiece in high temp pressure was hard to be circular shape, not like somebody dreamed for IR stealth。The rectangle nozzle was farfetched as stealth nozzle because of the exhaust gap appeared on F-117。 Yes, if L/W ratio approach the exhaust gap like F-117, you do gained IR reduced, but we say the nozzle on F-22 is a rectangle nozzle rather than a gap on F-117。But now, F-22 lost its capability of horizontal vectoring thrust.
Obviously, the OVT bring an ability of omni-maneuverability to do "helicopter" maneuver without loop previously.
Fifthly, YF-23 like back
The acr-shaped slope at up-surface will be a lift coming according the principle of Bernoulli. YF-23's design used it well but overrun. PAK·FA inherited it with slight humpback not only got drag reduced also obtained an additioanl lift from fuselage.
Last but not least
A relatively big angle for swept wing.
We know area ratio used for capability of transonic and supersonic good, but nobody noticed waspish design works for transonic good whereas there is another way design airframe like arrow same as Eurofighter Typhoon did, also is an excellent way for supersonic fly. The principle here is, the more time or position of shockwave occur you delay, the more drag could be decreased. For the PAK·FA, a high-swept wing will works for a real supercruise not like F-22 doing supersonic although without afterburner but still with range reduced compare to none-supersonic fly.
नटराज सबसे अच्छा नाम होगा...! मैं समर्थन करता हूँ...!
abhijitm wrote:meanwhile I dont get conflicting reports about indian participation in pak-fa. It was 50-50, then 25% and now we in talk with Russia?
After favouring the U.S. for its recent purchases of hi-tech military equipment, India has now turned to Russia, its old supplier, for the next generation fighter aircraft.
PAK FA, Russia’s fifth generation fighter, which boasts of radar evasion characteristics, made its maiden flight only late last month.
India inked an agreement with Russia for jointly developing this aircraft, but the time taken to complete the paperwork meant that 70 per cent of the plane was already developed by the Sukhoi Design Bureau. Now India has planned to enter the project mid-way. It will discuss the development schedule for the coming years and the number of aircraft it requires with Deputy Prime Minister and Russia’s India point man S.S. Sobyanin when he visits India by the middle of this month, senior government sources said.
Though its force levels are depleting, the Indian Air Force wants to ensure that the replacements are world-class and the best in the region. The 250-plus Sukhoi-30 MKI fighter aircraft to be inducted gradually over the next decade fit the bill, and so will the 126 frontline multi-role fighter aircraft, which India plans to buy and for which six vendors are in the fray.
PAK FA, billed as a competitor to F-22 Raptor, developed by the U.S., is expected go into mass production after at least five years. The striking feature of this aircraft is its stealth characteristics: radars will find it tough to spot it. It will also be able to take off from short airstrips and remain in the air for longer than the current fighters in the inventory of air forces around the world. What has attracted India to the project is the cost factor: it will be a lot cheaper to make than F-22.
Besides the talks on the aircraft, the military-technical team accompanying Mr. Sobyanin will hold discussions on more T-90 tanks, the naval version of MiG-29, Sukhoi-30 MKI and the multi-role transport aircraft project, said the sources.
The two sides have agreed on the price for refurbishing the aircraft carrier Gorshkov. Russia is poised to deliver more frigates to the Indian Navy. It will also transfer a nuclear-powered submarine to India by the middle of this year.
Recently India has favoured the U.S. while buying medium and heavy-lift planes and long-range maritime reconnaissance aircraft. U.S. companies are also in the race for several types of helicopters and refuelling planes. But officials say the list of military ventures with Russia is still longer and more varied.
Most notable difference between F-22 and PAK-FA/FGFA is that the later is an all weather day-night capable while the former is not.
The F-22 squad lead has to look at time,week,day/night,rainy/sunny/snowy/........... to give a take off signal
Going to Extremes
Each of the environmental tests begins just like an F/A-22 flight. The pilot and crew chief perform a walk-around of the aircraft then the pilot climbs the ladder and straps into the cockpit—regardless of the conditions in the chamber. The pilot starts the engines and operates various systems on the aircraft in each weather condition. “Part of the tests are to run the checklists,” adds Poulson. “We want to see how the cockpit warms up and how the aircraft warms up. If it is raining, the pilot gets wet.”
The aircraft is subjected to all manner of weather extremes in a battery of separate tests. The individual trials range from cold soaking the aircraft at minus sixty-five-degree cold before “warming” it to minus forty degrees; to a buildup of eight inches of snow, which at about twenty pounds of weight per square foot over the approximately 1,000 square feet of surface area on the Raptor results in a load of 20,000 pounds on the top of the aircraft; to a wind-blown snow at approximately forty-four feet per second. And that’s just the cold stuff.
After the snow melts (and is cleared through large drains in the chamber floor to a special retaining pond), heat test-ing begins. The trials start at a comfortable eighty degrees and build up to 120 degrees with the engines running. A later battery of tests subjects the aircraft to ninety-five degrees with seventy-four percent relative humidity and 105 degrees with eighty percent humidity to see where condensation occurs inside the aircraft.
Then the rains come. In one test, Raptor is inundated with 1.4 inches of rain per hour for close to eight hours to see how the drain holes on the bottom of the aircraft perform. Wind-blown rain tests identify where puddles may form in the weapons bays and in other openings. These tests are followed by an overnight in freezing rain. The resulting ice requires almost 1,200 gallons of deicing fluid to thaw the aircraft. The ice test is followed by a ground fog test at zero degrees and a vortex icing test (where the engines suck in standing ground water) to see where ice forms in the engine inlets.
A significant portion of the history of the F-22 spent years encased in a collection of wooden boxes stacked in a small storage closet in the engineering building at Lockheed Martin Tactical Aircraft Systems. The containers conceal a variety of design study models dating back to the earliest phases of the Advanced Tactical Fighter-to what eventually became the F-22 Raptor.
The official beginning of the ATF program usually traces to 1981 when USAF Aeronautical Systems Division, or ASD, released a request for information for concepts for an advanced tactical fighter. (ASD is now the Aeronautical Systems Center at Wright-Patterson AFB, Ohio.) The term advanced tactical fighter and its abbreviation, ATF, however, appeared in a general operational requirements document issued to contractors by the Advanced Planning Branch of ASD almost ten years earlier in 1972. The requirements document pertained to a new air-to-ground fighter to complement the new F-15 air-superiority fighter. The ATF would replace an aging fleet of F-4 and F-111 aircraft.
NRao wrote:The worst thing seems to be misinformation ................................
Users browsing this forum: No registered users and 9 guests