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  • in reply to: comparison of combat jet engines #2378620
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    Wow, and engine that is over twice the weight and occupying about 3.5 times the space develops a little over twice the power, how amazing.

    i wouldn´t hold it against them, higher bypass makes em bigger. And therefore alot more energy effective..

    in reply to: comparison of combat jet engines #2379541
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    What is the smallest and with suited aerodynamics craft that could take the mighy F119? with alot of mod i might add :dev2:

    F-104 or Draken? 😮

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    Wedgetail gives a 360 degree view i think, has many more arrays than the erieye, and from the delays and cost over runs its clear that it is a truly original and unique defence program (that seems to be the primary property of every new defence project around the world, its cost and time over-runs).

    the frontal and aft view isnt that good, but yes 360 deg. about 140 deg on each side is good range.

    in reply to: MMRCA News And Discussion V #2379662
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    If “smart” programing(modular layers) are used, not much will be needed to change.
    in the backend i mean..
    Interlacing can be tricky thou..

    in reply to: MMRCA News And Discussion V #2380389
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    With the same generation and class of technology, the bigger fighter often has:

    1. More fuel for the more powerful electrical generator and cooling system to generate more power and better cooling function.

    2. More space and loading to equip the bigger, heavier, and more powerful electrical generators and cooling systems.

    well, that is certainly true. But the requirements of compactness makes engineers strive more…
    Still i dont like oversimplistic calculations.
    PS-05a have today about the same range as Captor M, so i dont see this change in the future..

    in reply to: MMRCA News And Discussion V #2380432
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    1,500 should be the number of T/R modules for APG-77 in 1990s.

    As the new GaAs T/R modules today have become much more lighter and smaller, I think it is completely possible that the APG-77 will be able to have much more than 1,500 T/R modules (> 2,000 I think) if it adopts the new GaAs T/R modules today.

    In the end, I think the difference of detective and tracking range among APG-77, CAPTOR AESA, and Raven still mainly depends on the difference of electrical power of their own fighters (F-22A, EF-2000, and Gripen NG) ~ The GaAs T/R modules can’t generate electricity and power on their own, and the larger fighter often has more space and capacity to equip the bigger and more powerful electrical generators.

    If your electrical generators are not powerful enough, then your AESA radar’s detective and tracking range won’t be longer even being equipped with many thousands of GaAs T/R modules……

    i dont think power is the problem, compactness and cooling solution is a bigger factor.

    in reply to: MMRCA News And Discussion V #2380433
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    Simplistic vision it might be, but in this case is also correct.
    What i dont understand is why you have brought into this discussion the 192 TRM´s (yes, not 200) E/F frequency of the Erieye.
    Completely diferent frequency and power output.
    On the other hand the Raven and the AESA Captor will be using the exact same TRM´s , and the backends will be of the same technological generation.
    Not only that, but the electrical output available in the Typhoon is vastly superior, and dont mention the space in the nose for the backend.
    So we have an antenna with 50% more TRM´s, more electrical power and more space (electrical power and more space will translate in better cooling).

    Like i´ve said, “Unless Selex screws up the entire CAPTOR AESA design this radar will have more range by comparison with the Raven”.

    Same generation isnt the same…still its oversimplistic. yes, its 192 trms in a Erieye but it does not change my point.
    Captor E will probably be a very good radar but you cant say its 36% better than Raven, just because it got 36% highter TRM count…to many variables determing range.

    in reply to: MMRCA News And Discussion V #2380744
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    By definition the more TRM´s on an antenna, the bigger the power output, and this equates into more range.

    Unless Selex screws up the entire CAPTOR AESA design this radar will have more range by comparison with the Raven.

    that is a simplistic way to see it.
    A Erieyeantenna have only 200 trm…and it got alot more power than captor E

    A super exact sinussignal is generated by a exiter and is distributed eatch TRM. Depending on the TRM gain the power out can be +10db or +200db from every TRM. Multiply The no of trm to that output. And that is not the end of it. You have to ad the time of the signal is sent.

    So Exiter output*TRM gain*no TRMS*time of exposure= energy output

    At the reciever-side depening on how clean signal was generated in the exiter
    and its own sensitvity it can have anything between 20db-200db dynamic range.
    So you can have a weak output and clean signal, a great receiver and you have still good range.

    So range is depending on much more things than TRM count.

    in reply to: MMRCA News And Discussion V #2380886
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    The Phoon AESA antenna should be +-50% bigger. That brings more power, range, etc.

    They seems to offer less scan volume only >180deg and not 270deg as SAAB/SELEX solution..this must be the different backends…
    the TRMs would probably be very alike but more TRMs.
    But this does not necessarly mean better range, due to different backends/EXR/SDU.
    It only mean better beamforming(more TR antennas) and better antenna gain.

    in reply to: Canards and stealth. . . #2380905
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    The moment arm of any control surface will be related to the distance between the aircraft`s center of gravity and the center of lift of the control surface and it does not matter if the control surface center of lift it`s ahead or behind the center of gravity.
    it is the same with a flap`s moment arm.
    A longer arm is the one which is farther from the center of gravity.

    unstable aircraft have their wings center of lifts ahead of the center of gravity, so the wing is closer to the center of gravity, thus this makes their trailing edge flaps closer to the center of gravity.
    in example the Viggen-Gripen or Mirage III-Mirage 2000

    On a stealth fighter like the T-50 or F-22, TVC will do the supersonic trim and the tailplanes the roll.
    On aircraft like Rafale, the canard is very close coupled with the wing and the wing its moved forward to created relaxed stability, if the Rafale gets a high ITR it`s thanks to a huge wing and relaxed stability coupled with an excellent TWR and low drag airframe.

    Mirage 3 and viggen have in priniple the same controls. stable delta.

    Rafale and gripen have also in principle the same. unstable close-coupled canard and delta.

    in reply to: Canards and stealth. . . #2380913
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    do large delta wings also affect RCS negatively?

    No, and canards effect rcs depending on specific design solution.
    The High RCS/canard thing is a myth.
    And only a american marketing glimic to say anything else. (otherwise they keep that knowlege by them selfs, and really want ROW to build canard reflectors..)
    SU-35 did suffer of the canard/high RCS but, this is only a specific design case.

    in reply to: HELLENIC AIR FORCE NEWS & DISCUSSION #2384751
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    In addition, in a lesson of marketing from which everyone should learn something (yes Dassault, i am speaking of you), after the display on Thessaloniki’s Defensys exposition, a cockpit simulator of the F35, will be transported to 110 Combat Wing at Larissa AB (which also happens to be HAF’s Tactical Air Command) and be left there for “a period of time”, so that greek pilots will have the opportunity to get acquainted with the F35 at their leasure.

    Yes, we ‘re bankrupt, but they insist, not my fault!

    Can i come, can i come 🙂

    in reply to: MMRCA News And Discussion V #2385387
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    It depends how they are used, and how many tasks they are given at any given time.

    There’s definately room in the cheeks of the Rafale (for instance) to fit a good size array for 180+° coverage, especially if you can remove the AESA antennaes of SPECTRA as they become redundant.

    To me a swashplate is a transitional step until 360° coverage is achieved. Convenient for a while until the rest gets to the next step.

    And all that doesn’t diminish the fact that with modern tactics, scenarios as envisionned by aspis earlier in the thread (1vs1 frontal BVR fight) get more and more unlikely, especially with stealth planes.

    Nic

    problems with side arrays..

    First, you want all your TRMs in the same array to maximise energy output in one beam. Everything else is stupid, pardon me.. The only time anything else is smart is when you have enough energy for one beam to see a stealth cruisemissile just beond the horizon..

    second, weight.
    i dont need to get in to that.

    problems with ASEA 180 deg scans..

    The range of ASEA deminishes massively outside frontal lobe..

    in reply to: Saab JAS 39 Gripen Info # 2 #2386076
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    i like the eye´s better..

    in reply to: Saab JAS 39 Gripen Info # 2 #2386122
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Viewing 15 posts - 526 through 540 (of 1,400 total)