Russia Defence Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.

Military Forum for Russian and Global Defence Issues


+62
Daniel_Admassu
lyle6
GarryB
LMFS
gc3762
KoTeMoRe
lancelot
TMA1
PeregrineFalcon
Backman
Hole
dino00
Tai Hai Chen
Scorpius
Arrow
thegopnik
Isos
nero
zepia
FFjet
secretprojects
Begome
Gomig-21
limb
Mindstorm
SeigSoloyvov
wilhelm
jaguar_br
tomazy
Stealthflanker
PapaDragon
owais.usmani
Sujoy
AlfaT8
Singular_Transform
The-thing-next-door
marcellogo
RTN
Azi
ahmedfire
x_54_u43
ultimatewarrior
JohninMK
Austin
Tsavo Lion
Giulio
jhelb
tanino
kvs
mnztr
Rodion_Romanovic
PhSt
Vann7
Viktor
Big_Gazza
archangelski
magnumcromagnon
miketheterrible
calripson
william.boutros
George1
ult
66 posters

    Su-57 Stealth Fighter: News #6

    Isos
    Isos


    Posts : 9430
    Points : 9414
    Join date : 2015-11-06

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Isos Sat Nov 28, 2020 7:31 pm

    Su-27 is around 15m2. Su-57 according to sukhoi is 0.1-1m2 (best-worst cases I think).

    Su-57 is like 100 times stealthier than su-27.
    avatar
    Arrow


    Posts : 1403
    Points : 1397
    Join date : 2012-02-12

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Arrow Sun Nov 29, 2020 3:19 am

    LMFS wrote:Old roadmap for turbine technologies allowing for gas temperatures > 2000K like in F135. I don't know where Russia stands here but related to izd. 30 I find it interesting that the ideas to reach such temperatures seem to be so clear...

    So it looks like the F-135 is the most advanced military aircraft engine in the world. At least until we know the performance of izd 30.
    Scorpius
    Scorpius


    Posts : 682
    Points : 682
    Join date : 2020-11-05
    Age : 34

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Scorpius Sun Nov 29, 2020 4:18 am

    Isos wrote:Su-27 is around 15m2. Su-57 according to sukhoi is 0.1-1m2 (best-worst cases I think).

    Su-57 is like 100 times stealthier than su-27.

    0.1-1m2 - these are the average values for the entire construction type. This does not mean that the best indicator for the su-57 is only 0.1 m2.
    Isos
    Isos


    Posts : 9430
    Points : 9414
    Join date : 2015-11-06

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Isos Sun Nov 29, 2020 4:22 am

    Scorpius wrote:
    Isos wrote:Su-27 is around 15m2. Su-57 according to sukhoi is 0.1-1m2 (best-worst cases I think).

    Su-57 is like 100 times stealthier than su-27.

    0.1-1m2 - these are the average values for the entire construction type. This does not mean that the best indicator for the su-57 is only 0.1 m2.

    That's what counts. The aircraft would move in the air and will never be in the perfect conditions as when they measured the best rcs.

    0.1 is perfect. And it doesn't have weapons to increase it under the wings.
    LMFS
    LMFS


    Posts : 4497
    Points : 4497
    Join date : 2018-03-03

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  LMFS Sun Nov 29, 2020 5:34 am

    Arrow wrote:So it looks like the F-135 is the most advanced military aircraft engine in the world. At least until we know the performance of izd 30.

    Yes of course, at least if the claimed values are true. TWR is above 11, TIT is 3600F, OPR is 28... values head and shoulders above any comparable engine. As you say we need to see what izd. 30 brings, in the end AL-41F1 is not really a new design but an AL-31 variant.
    Isos
    Isos


    Posts : 9430
    Points : 9414
    Join date : 2015-11-06

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Isos Sun Nov 29, 2020 6:38 am

    US are the most advanced in aircraft engines. They are leaders in that field and they have lot of money from civilian engines.

    Russia is recovering from USSR death.

    EU are too stupid to launch a europen company to produce engines for airbus and let the big piece of cake to US and UK.
    JohninMK
    JohninMK


    Posts : 10841
    Points : 10962
    Join date : 2015-06-16
    Location : England

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  JohninMK Sun Nov 29, 2020 7:42 am

    Having to run the F-135 at those temperatures sure produces an interesting hot air plume behind it. Surely a major problem in an IR world, negating much of the 'stealth' features?
    Isos
    Isos


    Posts : 9430
    Points : 9414
    Join date : 2015-11-06

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Isos Sun Nov 29, 2020 8:36 am

    JohninMK wrote:Having to run the F-135 at those temperatures sure produces an interesting hot air plume behind it. Surely a major problem in an IR world, negating much of the 'stealth' features?

    That's true for any aircraft.

    IR signature can't be really hidden. Their engines heat a lot and modern IR cameras/sensors are very good and getting better every year.
    Tai Hai Chen
    Tai Hai Chen


    Posts : 305
    Points : 305
    Join date : 2020-09-21
    Location : China

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Tai Hai Chen Sun Nov 29, 2020 9:30 am

    Unfortunately it doesn't seem like they would be able to deliver the first production Su-57 this year. Bummer that. Was really looking forward to it.
    dino00
    dino00


    Posts : 1677
    Points : 1714
    Join date : 2012-10-12
    Age : 34
    Location : portugal

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  dino00 Sun Nov 29, 2020 10:28 am

    Tai Hai Chen wrote:Unfortunately it doesn't seem like they would be able to deliver the first production Su-57 this year. Bummer that. Was really looking forward to it.

    Where do you see that?
    LMFS
    LMFS


    Posts : 4497
    Points : 4497
    Join date : 2018-03-03

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  LMFS Sun Nov 29, 2020 1:18 pm

    JohninMK wrote:Having to run the F-135 at those temperatures sure produces an interesting hot air plume behind it. Surely a major problem in an IR world, negating much of the 'stealth' features?

    Sure, but they have some countermeasures like a cooled blocker inside of the nozzle and a layer of could air surrounding the exterior. Despite the increased risk of detection, temperature is one of the few ways you can increase the efficiency and thrust of an engine so it is the way to go.
    Hole
    Hole


    Posts : 6461
    Points : 6449
    Join date : 2018-03-24
    Age : 46
    Location : Scholzistan

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Hole Sun Nov 29, 2020 2:02 pm

    Su-57 Stealth Fighter: News #6 - Page 30 Su-57_23

    kvs and thegopnik like this post

    Isos
    Isos


    Posts : 9430
    Points : 9414
    Join date : 2015-11-06

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Isos Sun Nov 29, 2020 2:09 pm

    Nice picture but what impresses me is the flat terrain behind. S-400 woukd be happy to sit there and kornet would be usefull at very long range.
    Backman
    Backman


    Posts : 1101
    Points : 1107
    Join date : 2020-11-10

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Backman Sun Nov 29, 2020 2:29 pm

    On the su 57 RCS vs F-22 or F-35
    The original tender by the USSR for the 5th gen aircraft called for capability parity with the F-22. Which makes sense because parity with the US has been USSR/Russia military doctrine since Stalin.

    Sure the F-22 is more stealthy from the back and all that. But generally , the su 57 isn't going to be any less stealth than the F series. Unless you think Sukhoi knowingly stopped short of fulfilling the requirements of the tender which also makes Russia in violation of its most basic military doctrine.

    But there are still morons online who think the F-22 is multiple standard deviations more stealth than the su 57 because some airforce jock told the Discovery channel that the F-22 is the size of a golf ball on radar. Which they convert to 0.000000000001 RCS


    Last edited by Backman on Sun Nov 29, 2020 6:42 pm; edited 1 time in total
    Tai Hai Chen
    Tai Hai Chen


    Posts : 305
    Points : 305
    Join date : 2020-09-21
    Location : China

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Tai Hai Chen Sun Nov 29, 2020 3:47 pm

    Backman wrote:On the su 57 RCS vs F-22 or F-35
    The original tender by the USSR for the 5th gen aircraft called for capability parity with the F-22. Which makes sense because parity with the US has been USSR/Russia military doctrine since Stalin.

    Sure the F-22 is more stealthy from the back and all that. But generally , the su 57 isn't going to be any less stealth than the F series. Unless you think Sukhoi knowingly stop short of fulfilling the requirements of the tender which also makes Russia in violation of its most basic military doctrine.

    But there are still morons online who think the F-22 is multiple standard deviations more stealth than the su 57 because some airforce jock told the Discovery channel that the F-22 is the size of a golf ball on radar. Which they convert to 0.000000000001 RCS

    F-22 has pretty big RCS. Same as F-15 if not bigger. If you want small RCS go for a small plastic drone like TB2. It's virtually undetectable by radar.
    GarryB
    GarryB


    Posts : 33258
    Points : 33772
    Join date : 2010-03-30
    Location : New Zealand

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  GarryB Sun Nov 29, 2020 11:03 pm

    That's true for any aircraft.

    IR signature can't be really hidden. Their engines heat a lot and modern IR cameras/sensors are very good and getting better every year.

    A turbojet makes the air flowing through it very hot but a turbofan has air flowing through the hot section but also cold air that bypasses the hot section so it blows higher density cold air as well as hot air which mixes in the exhaust and creates a large volume of moving airflow which = thrust.

    When a turbofan uses afterburner the cold dense air is oxygen rich and you can dump more fuel in the exhaust in the AB to create rather more thrust than a turbojet.


    If you want small RCS go for a small plastic drone like TB2. It's virtually undetectable by radar.

    Hahahaha... the plastic surface might not reflect radar, but radar waves go right through and what sort of radar cross section do you think your average engine has with all its bumps and curves... it is tiny hand held drones that use batteries and electric motors that are hard to detect with radar... big drones like TB2 are only hard to spot by air forces like NK or a broken country like Libya.

    In most normal countries a TB2 would be detected easily and even a MiG-21 or Su-17 could chase it down and shoot it down.

    Smaller drones would be much harder to find and engage.
    PhSt
    PhSt


    Posts : 649
    Points : 655
    Join date : 2019-04-01

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  PhSt Sun Nov 29, 2020 11:04 pm

    Su-57 Stealth Fighter: News #6 - Page 30 275675

    GarryB, Big_Gazza, zepia and Backman like this post

    kvs
    kvs


    Posts : 12887
    Points : 13034
    Join date : 2014-09-10
    Location : Kanada

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  kvs Sun Nov 29, 2020 11:48 pm

    Backman wrote:On the su 57 RCS vs F-22 or F-35
    The original tender by the USSR for the 5th gen aircraft called for capability parity with the F-22. Which makes sense because parity with the US has been USSR/Russia military doctrine since Stalin.

    Sure the F-22 is more stealthy from the back and all that. But generally , the su 57 isn't going to be any less stealth than the F series. Unless you think Sukhoi knowingly stopped short of fulfilling the requirements of the tender which also makes Russia in violation of its most basic military doctrine.

    But there are still morons online who think the F-22 is multiple standard deviations more stealth than the su 57 because some airforce jock told the Discovery channel that the F-22 is the size of a golf ball on radar. Which they convert to 0.000000000001 RCS

    These morons ignore the absurdly oversized F-22 rudders and fixate on the circular nacelles of the Su-57 engine.   Of course
    the F-35 having a circular nacelle is just compartmentalized as "other" in their peanut sized brains.   The size of the rudders
    matters since primitive stealth (F-117A) is effective only if the EM is reflected away from the radar.  But radar beams
    coming from multiple locations and distances can scatter to other radars.    At the end of the day the cross-section matters
    and the Su-57 has a much lower cross-section from the side than the F-22.

    Big_Gazza and Backman like this post

    LMFS
    LMFS


    Posts : 4497
    Points : 4497
    Join date : 2018-03-03

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  LMFS Mon Nov 30, 2020 6:38 am

    Any aperture where an antenna is placed needs to be radio transparent at that frequency, in the case of the main radar that is like 1 sqm full with metal reflectors, plus all the ECM/ESM and communications apertures, plus all the gaps and access panels, plus all the LE, plus cockpit plus the intakes, plus... and they say it all has the reflective surface of a marble? Sure...
    Backman
    Backman


    Posts : 1101
    Points : 1107
    Join date : 2020-11-10

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Backman Mon Nov 30, 2020 10:27 am

    Some plonkers on Twitter were bringing up the alleged issues with the su 57 canopy again. Because the su 57 has a canopy pillar and the F-22 doesn't. And neither does the J-20, they've concocted this idea that pillar= bad.

    Funny that. Here is the YF-23 canopy. The same YF-23 that had better all aspect stealth than the F-22.

    Su-57 Stealth Fighter: News #6 - Page 30 ?u=https%3A%2F%2Fstatic.rcgroups.net%2Fforums%2Fattachments%2F4%2F3%2F5%2F6%2F1%2F4%2Fa5872739-231-canopy%2520b

    Su-57 Stealth Fighter: News #6 - Page 30 5d652af8dda4c812748b458c

    magnumcromagnon, Big_Gazza, kvs, zepia, miketheterrible and thegopnik like this post

    kvs
    kvs


    Posts : 12887
    Points : 13034
    Join date : 2014-09-10
    Location : Kanada

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  kvs Mon Nov 30, 2020 10:38 am

    The same fanboi retardation.  Fixate on a small part of the jet and ignore the rest of it.   One tiny, stupid thought at a time
    is what they can process in their microscopic buffer.


    Last edited by kvs on Tue Dec 01, 2020 10:42 am; edited 1 time in total

    Big_Gazza likes this post

    GarryB
    GarryB


    Posts : 33258
    Points : 33772
    Join date : 2010-03-30
    Location : New Zealand

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  GarryB Mon Nov 30, 2020 10:58 pm

    Same complaints about older Soviet fighters but mostly from ignorance.

    A canopy is not just clear material you see the world through while flying an aircraft.

    A canopy has to be strong enough to withstand impacts with large birds, but also be thin enough to see through easily.

    The two section canopy of the Su-57 has a front section that will be very strong to withstand impacts on takeoff and landing with birds, while the main transparency can be made thinner and easier to see through.

    The one piece canopy of say an F-16 needs to be thick which makes it fantastic to look through, but it also makes it heavy... if you make the front thicker and stronger to resist impacts and the rest thinner so it is easier to see through then you get distortions and the wrong impression of where things are... like looking into water bends light so the fish is not where it appears to be.

    The fact of the matter even a fully strapped in pilot can move their head up and down quite a distance so anything behind the structure can be revealed simply by bobbing ones head occasionally... of course the structure blocking the pilots view is well within the field of view of the nose mounted radar and IRST so even if a target managed to get into that tiny blind spot it will still be detected and tracked so the problem is really only a problem for some people...
    avatar
    PeregrineFalcon


    Posts : 12
    Points : 12
    Join date : 2020-11-14

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  PeregrineFalcon Wed Dec 02, 2020 9:47 am

    LMFS wrote:No worries, we all answer when we can, if we can  thumbsup

    Again, sorry for the late replay, I was few days on the field hunting with the birds of prey!

    LMFS wrote:I see no problem, see the "static stability" part in the text you quote. In general I am making no assumptions as to how much lift the canard generates at a given speed, altitude, load etc. in the Eurofighter. My point is that canard is creating a positive contribution to lift instead of a negative one.

    Exactly, but my point on the other hand was that at certain conditions positive canard deflection can have negative impact on the main wing thus reducing the overall lift.

    LMFS wrote:@GarryB, @PeregrineFalcon:

    the guy linked by zepia keeps delivering, watch this about the foreplanes:

    https://www.youtube.com/watch?v=Ny0NjjjJqaA

    Very nice chanel, although the video you linked is not very helpful for our discussion [yours and mine], his other video actually is  Wink



    Look at 11:15

    LMFS wrote:You have a point there, I had not fully realized the plane of the canards is higher than the wing but the tips are quite low, I wonder why this very marked anhedral angle... maybe for roll stability reasons?

    I don't think they had stability on their mind because anhedral angle is used for the opposite reason [unlike dihedral angle], but maybe they wanted to direct canard vortex closer to the main wing when the plane is at higher AoA for increased maneuverability. If the canard tips vere at the same plane as the canard root, the vortex interaction with the main wing would most probably be absent at desired level.
    When the flow above the main wing has begun to experience turbulence, the vortex core from the canard will hit the flow above the wing and make it re-streamline.

    [img]Su-57 Stealth Fighter: News #6 - Page 30 2012-0825-EADS-Aerospace-ANSYS-CFD[/img]

    I will have to point out that this is just my theory that can be wrong?!

    Anyway, I think that the PAK FA solution is the most "elegant" one regarding performance and also RCS!
    Backman
    Backman


    Posts : 1101
    Points : 1107
    Join date : 2020-11-10

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Backman Wed Dec 02, 2020 2:32 pm

    I like how the Millennium 7 guy is having none of this nonsense about the su 57 not being LO enough. He casually uses both the F-22 and su 57 when he's explaining stuff about stealth. Like the intakes for example.

    Su-57 Stealth Fighter: News #6 - Page 30 F_2257intake_by_backspin321_de9rjjj-pre.jpg?token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJ1cm46YXBwOiIsImlzcyI6InVybjphcHA6Iiwib2JqIjpbW3siaGVpZ2h0IjoiPD03NDEiLCJwYXRoIjoiXC9mXC82NzMyZjYzZi1kNTRmLTQ3ODktYjRlYS1kZTRlMjEzMzJkOTZcL2RlOXJqamotY2U3ZTgzOTQtMmRmZC00ZmVhLWEzYWMtMThlZDMwNWQ0MjhjLnBuZyIsIndpZHRoIjoiPD0xMTk0In1dXSwiYXVkIjpbInVybjpzZXJ2aWNlOmltYWdlLm9wZXJhdGlvbnMiXX0
    kvs
    kvs


    Posts : 12887
    Points : 13034
    Join date : 2014-09-10
    Location : Kanada

    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  kvs Wed Dec 02, 2020 3:02 pm

    The whole "debate" is moronic. As if the people who wrote the book (manual, whatever; it was not Americans or NATzO members)
    on the stealth EM applied mathematics cannot conduct simulations using those equations to test any design they produce.
    Somehow those equations are good enough when Americans use them, but become worthless when their authors use them.
    NATzO fanbois are certifiable retards or frothing at the mouth haters.

    LMFS likes this post


    Sponsored content


    Su-57 Stealth Fighter: News #6 - Page 30 Empty Re: Su-57 Stealth Fighter: News #6

    Post  Sponsored content


      Current date/time is Sat May 28, 2022 9:41 am