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Su-57 News and Discussion -version_we_lost_count!-

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  • LMFS
    Rank 3 Registered User

    @paraly:

    Interesting, do you have any reference or picture of the tanks in the weapons bays?

    @haavarla:

    increase over range of the same plane with the first stage engine.
    I also think the PAK-FA is a great design but internal fuel is a little less than Flanker (Su-35) and the plane is a little heavier, probably due to internal weapons and other compromises due to LO design. Of course, internal carriage has a positive effect on range in real conditions. In regards of L/D and other aero parameters, I have no hard data, apart from a slight reduction of the cross sectional area compared to the T-10 platform.

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    • paralay
      Rank 5 Registered User

      Interesting, do you have any reference or picture of the tanks in the weapons bays?
      There is no image of the inner tank. Obviously, he repeats the geometry of the weapon bay. Weight of fuel in one such tank 1500 - 1800 kg. Insiders reported that the T-50 was flying with this tank from Komsomolsk-on-Amur to Zhukovsky

      Comment

      • Marcellogo
        Rank 5 Registered User

        I have no idea how this relates to my post.
        Just that I would not cite all the ongoing discussion about the order of two first-serial planes, so I have taken just the last post related to it.
        Any comparation between the LRIP 1 F-35 and them is just out of question as the former are at a very initial configuration, never intended to have any operative role while the others would be practically identical to the serial assembled one (with -117 engine obviously), just they would be used to test proof the assembly line.

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        • LMFS
          Rank 3 Registered User

          @paralay:

          Thanks! Great feature for ferry flights and other missions where amount of weapons is not critical, especially considering that Su-57 has two additional bays for SRAAM. Had thought of this before but was not aware of any stealth plane that had it implemented

          Comment

          • garryA
            Rank 5 Registered User

            Originally posted by paralay
            2 external tanks - 4100 km
            4 external tanks - 4700 km
            range at the super-high speed is 2150 km (Pogosyan - 1500 km)
            What TSFC and drag curve did you used for these calculation and where did you get them from?
            Can you elaborate your calculation in details?

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            • JSR
              JSR
              Rank 5 Registered User

              Calculation:
              without external tanks - 3250 km (Pogosyan spoke 3,500 km)
              1 tank in the weapons bay - 3700 km
              2 external tanks - 4100 km
              4 external tanks - 4700 km
              range at the super-high speed is 2150 km (Pogosyan - 1500 km)
              two external tanks add 900km range to Su-35. there is no way it is adding less range to T-50 when takeoff distance of T-50 is 300m while SU-35 is 425m.
              https://www.youtube.com/watch?v=krSf7uHZYB8

              Comment

              • paralay
                Rank 5 Registered User

                Gentlemen, offer your results and we will discuss them. The approximate weight of the aircraft and the weight of the fuel, let's count together

                Comment

                • rpgtype7v
                  Rank 3 Registered User

                  As said, this is very cool, but you don't throw to the bin something just because you just discovered something better. There is a thing called life cycle of a technology. Some technologies are dying, others are actively used and others are being developed.

                  See no relation to cancellation of PAK-FA. Which, by the way, is utter nonsense to me, to make it clear.

                  On the contrary, I can imagine that you can go and develop structures designed in this way to substitute conventional ones that can be exchanged 1 to 1 during some mid-life overhauling. More resistance and less weight. No need to cancel any plane...

                  -------------------------------------------------------------------------------


                  why not, pak-fa is conservative and is basically early 2000s in materials... imagine improvements there.

                  Click image for larger version

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                  40-44% aluminium
                  22-26% composite
                  18% titanium
                  10% steel
                  4% other


                  comparison-EUROFIGHTER TYPHOON:

                  GENERAL MATERIALS
                  Carbon Fibre Composites
                  70%
                  Metals
                  15%
                  Glass Reinforced Plastics (GRP)
                  12%
                  Other Materials
                  3%
                  Last edited by rpgtype7v; 28th August 2018, 18:46.

                  Comment

                  • rpgtype7v
                    Rank 3 Registered User

                    Since the first flight last year there are no news... only that they continue testing!

                    the plane is not stealthy looking like this and with this engines - period ... it was supposed to have a something composite absorber that look a like a pangolin animal skin around it engines to enable all-round vectoring but keep stealth and infrared reduction- but who knows whats happened.
                    http://r.ddmcdn.com/s_f/o_1/APL/uplo...TICLE-PAGE.jpg
                    Last edited by rpgtype7v; 28th August 2018, 18:52.

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                    • a89
                      a89
                      Rank 5 Registered User

                      The S-111 data link for PAK FA has been tested (completely I assume):

                      https://tvzvezda.ru/news/opk/content...81440-ji8z.htm
                      History and Military Technology blog

                      alejandro-8en.blogspot.com

                      Comment

                      • XB-70
                        Rank 2 Registered User

                        40-44% aluminium
                        22-26% composite
                        18% titanium
                        10% steel
                        4% other


                        comparison-EUROFIGHTER TYPHOON:

                        GENERAL MATERIALS
                        Carbon Fibre Composites
                        70%
                        Metals
                        15%
                        Glass Reinforced Plastics (GRP)
                        12%
                        Other Materials
                        3%
                        Um, you are making the mistake of comparing percentages by weight (Su-57) to percentages by surface area (Eurofighter). Those are two very different things! The construction of the Su-57 matches other modern fighters.

                        Comment

                        • panzerfeist1
                          Rank 3 Registered User

                          @rpgtype7v


                          "it was supposed to have a something composite absorber that look a like a pangolin animal skin around it engines to enable all-round vectoring but keep stealth and infrared reduction- but who knows whats happened."

                          So let me get this straight. Your saying improvements are needed because the aircraft does not have enough composites like the Euro-fighter according to your 2 posts....Correct?

                          Have you checked the composite percentage on either the F-22 or F-35? I assure you that if I had an F-16.net account and I said that the aircraft's need more improvements in their composite material to match the eurofighter to be more stealthy than the eurofighter. I would have been crucified and burned alive in that forum.

                          With your chart comparison of materials saying imagine improvements, than talking about the air-crafts composites in your 2nd post saying but who knows what happened? For the sake of not to further embarrass yourself I hope your not suggesting he who has more composites is stealthier than the other because that is what it seems to me.

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                          • LMFS
                            Rank 3 Registered User

                            @rpgtype7v:

                            That is a cool slide! See XB-70 comments of weight vs area. The PAK-FA is almost totally composites in its surface, so probably above Typhoon values in that regard. And BTW, metals are quite OK for some uses, for instance landing gear has been "humble" steel for many decades and it doesn't seem this is going to change any time soon. The same for Alu or Ti alloys. Science moves forward in the field of metallurgy too, while cost / effectiveness always rules.

                            The only important point I would make is, that you cannot change the basic technologies of a fighter while you test it, period. Otherwise you never finish with your development, as previous results in your test program get voided because you changed such basic things as materials an structure of the plane, and you have to start again. This is simply incompatible with any development process. Once you settle for a design, it is frozen and it gets old. So is life!

                            Regarding the engines... I know the pangolin but thanks for the picture
                            Izd. 30 seems to address LO design issues both in rear and frontal aspect. Cannot comment on that specifically because:

                            1) Only known features of Izd. 30 in that regard are composite compressors + radar blocker at the front and serrated nozzles and "other technologies" at the rear, plus unidentified IR signature reduction measures. We know essentially nothing (at least myself)
                            2) Weight of stealth in Russian doctrine and angular aspects of interest are questionable at best. You don't get crazy to develop something you don't fully believe in to start with (or believe only in certain circumstances to be more exact)

                            All I can say with some certainty is LO design is addressed with izd. 30. Don't know to what extent and with what results.

                            Comment

                            • RALL
                              Rank 4 Registered User

                              Originally posted by XB-70
                              Um, you are making the mistake of comparing percentages by weight (Su-57) to percentages by surface area (Eurofighter). Those are two very different things! The construction of the Su-57 matches other modern fighters.

                              Actually the weight percentage of composite materials used in the construction of the Eurofighter is around 50% (70% surface), that's like 2 times (ratio weight percentage) more than composite materials used in the Su-57 according to that graph. People understimate the Eurocanard and really after F-22 and now F-35 it is a impresive airplane.
                              Last edited by RALL; 28th August 2018, 23:13.

                              Comment

                              • XB-70
                                Rank 2 Registered User

                                Actually the weight percentage of composite materials used in the construction of the Eurofighter is around 50% (70% surface)
                                Source? Because that is really high...building the frame and ribbing with such a high portion of composites in the frame and ribbing adds a lot of cost for little benefit. Composites tend to have really good tensile strength, but it is difficult to give them good compressive strength (you have to be an ace with your resin for this). And, although tensile strength is the more important of the two, you do need both. The F-35 only has 35% by weight; the F-22 25%.

                                Comment

                                • haavarla
                                  Rank 5 Registered User

                                  Out of the top of my head, something is off with that EF slide.. 50% of the total weight or mass of airframe is Composites, that is really high.
                                  You got any official source from Manufactors on this?
                                  Last edited by haavarla; 29th August 2018, 08:00.
                                  Thanks

                                  Comment

                                  • RALL
                                    Rank 4 Registered User

                                    Originally posted by XB=70
                                    Source? Because that is really high...building the frame and ribbing with such a high portion of composites in the frame and ribbing adds a lot of cost for little benefit. Composites tend to have really good tensile strength, but it is difficult to give them good compressive strength (you have to be an ace with your resin for this). And, although tensile strength is the more important of the two, you do need both. The F-35 only has 35% by weight; the F-22 25%.
                                    The airframe is built of about 50% composite materials by weight and about 70% by surface area, with substantial use of titanium and lithium-aluminum alloys elsewhere.

                                    http://www.airvectors.net/aveuro.html

                                    On last you can look original sources.

                                    And first flight of this airplane was 24 years ago...the only problem that is not VLO fighter. But on my opinion comparing with other 4+ fighters Typhoon is superior.
                                    Last edited by RALL; 29th August 2018, 07:57.

                                    Comment

                                    • XB-70
                                      Rank 2 Registered User

                                      @RALL - OK, I'll accept that. But then the follow on is: and what did they gain from that? The F-22 and such shows you can do just fine with around 25%. I'm not aware of anything where the Typhoon really stands out.

                                      Comment

                                      • RALL
                                        Rank 4 Registered User

                                        Originally posted by XB-70
                                        @RALL - OK, I'll accept that. But then the follow on is: and what did they gain from that? The F-22 and such shows you can do just fine with around 25%. I'm not aware of anything where the Typhoon really stands out.
                                        i do not know it, but from inside website of the Eurofighter typhoon, they tells this...

                                        THE AIRFRAME

                                        The aircraft is built with advanced composite materials to deliver a low radar profile and strong airframe. Only 15% of the aircraft’s surface is metal, delivering stealth operation and protection from radar-based systems. Pilots were included in the design from the earliest stages to develop a deliberately unstable airframe that can still be flown effectively. This delivers both superior manoeuvrability at subsonic speeds and efficient supersonic capability to support the widest range of combat scenarios.



                                        THE MATERIALS

                                        Strong, lightweight composite materials were key to the design of Eurofighter Typhoon to give it deliberate instability. Using them means the weight of the airframe is 30% less than for traditional materials, boosting range and performance as well as reducing the radar signature.


                                        PRODUCTION

                                        The innovative production techniques developed for Eurofighter Typhoon have created a whole new industry for the most effective use of advanced composite materials. These provide greater tensile strength and more aerodynamic performance with less weight and more reliability than traditional materials.



                                        THE TWIN EUROJET ENGINES

                                        Developing cutting-edge engine technology has been a key part of the Eurofighter Typhoon project from the start. Four global companies have jointly developed the high performance EJ200 power plants that each provide 90kN of thrust from a small lightweight engine with high strength and high temperature capability.

                                        The two-spool design with single-stage turbines drives the three-stage fan and five-stage HP compressor with annular combustion with vaporising burners. This allows Eurofighter Typhoon to cruise at supersonic speeds without the use of reheat for extended periods. The engines deliver 1,000 flying hours without needing unscheduled maintenance through the use of advanced integrated Health Monitoring for class-leading reliability, maintainability and Through Life Cost.



                                        https://www.eurofighter.com/the-aircraft

                                        Everybody talk about Raptor, and its ok, its normal because its a real VLO, but EF-2000 is a masterpiece.

                                        There are some video an EF-2000 with full load weapons and external tanks, doing some spectacular maneuvers. I did not see to any other aircraft doing it. And really this airplane is better in high altitudes, it was designed for it and supercruise. I like many this fighter, i am not impartial.

                                        Comment

                                        • Trident
                                          Rank 5 Registered User

                                          Originally posted by SpudmanWP View Post
                                          Now balance that against the cost of keeping all of the jets that the F-35 is to replace flying 10-15 years longer.
                                          Isn't at least the F-16 still cheaper to operate than the F-35?

                                          Originally posted by SpudmanWP View Post
                                          Damn, this belongs in the F-35 thread ;(
                                          It does.

                                          Originally posted by RALL View Post
                                          The airframe is built of about 50% composite materials by weight and about 70% by surface area, with substantial use of titanium and lithium-aluminum alloys elsewhere.

                                          http://www.airvectors.net/aveuro.html
                                          By "weight". What weight?

                                          OEW? Bare structure excluding engines & equipment? Typhoon does have more composites than the Su-57 (or most other fighters, for that matter) but - on a like-for-like basis - nowhere near double. For that to be the case, a very high proportion of its internal structure (beams, bulkheads, intake ducts) would have to be non-metallic and that is, as far as I know, not the case. Not to the extent that it would double its composite content (apples to apples) compared to the Su-57.

                                          Apart from that, conservatism in structural materials isn't necessarily a debilitating drawback, as others have noted. It didn't stop the Su-27 (probably the 4th generation fighter with the least composites) becoming a world beater, and conversely having a fairly high content didn't seem to help the MiG-29 very much either.
                                          sigpic

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