Announcement

Collapse
No announcement yet.

RuAF News and development Thread part 15

Collapse
X
Collapse
Currently Active Users Viewing This Thread: 5 (0 members and 5 guests)
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • haavarla
    Rank 5 Registered User
    • Dec 2008
    • 6715

    Truly smooth, the plane really seems to create LOTS of lift, losing very little altitude and speed when turning aerodynamically. By now very little hard maneouvering but rather elegant choreographies, I think we are far from knowing things like what the max sustained turning rate is.

    Max sustained Turn rate is no better vs Su-27S, its probably less when the Su-35S is carrying a lot of fuel, but similar at low fuel. Aerodynamical, the Su-35S is give or take 2 tons heavier, but it has four tons of extra thrust, and it is debatable if the TVC can actual help the sustained turn rate. Around the corners no doubt yes, but say you are in a merge and have to stick at it, perhaps not.

    But one thing is clear, no sane jet fighter pilot would do the verticals in the egg box against the Su-35S. The way it bends the top verticals is deadly effective. When you operate in the borders between sustained and instant turn rate that is where things get interesting with this jet.
    Last edited by haavarla; 25th August 2019, 01:49.
    Thanks

    Comment

    • LMFS
      Rank 4 Registered User
      • Feb 2018
      • 561

      Originally posted by haavarla View Post

      Max sustained Turn rate is no better vs Su-27S, its probably less when the Su-35S is carrying a lot of fuel, but similar at low fuel. Aerodynamical, the Su-35S is give or take 2 tons heavier, but it has four tons of extra thrust, and it is debatable if the TVC can actual help the sustained turn rate. Around the corners no doubt yes, but say you are in a merge and have to stick at it, perhaps not.

      But one thing is clear, no same jet fighter pilot would do the verticals in the egg box against the Su-35S. The way it bends the top verticals is deadly effective. When you operate in the borders between sustained and instant turn rate that is where things get interesting with this jet.
      Sorry that I was not clear, I was answering to the Su-57 video in the post just above mine. The plane moves as it was weightless, it is really amazing. But then, it has more than 80 sqm wing area, without really accounting the supersized, highly optimized lifting body. Empty weight cannot be very high either, seeing how it moves.

      But then the problem is that we don't know empty weights of either Su-57 or Su-35S. So we can argue about wing loading, sustained turn and TWR all that we want, without empty weight data it is all speculation. For instance for the Su-35S you are mentioning, we simply don't know the weight of the plane. We can speculate it is 18 tons, maybe it is but maybe not, original Flankers were > 16 tons, why would the Su-35S be much heavier? Some equipment was added on top of normal Flanker, some things were removed or optimized (i.e. all that extra fuel must use volume previously occupied with equipment), the air brake was removed too. Aero is not exactly the same as in regular Flankers either. As it is common, Russia makes sure a numerical analysis of their newest aircraft is not easy or certain.

      Comment

      • Austin
        Rank 5 Registered User
        • Oct 2003
        • 6506

        Photos: Missile bombers and special boards: how Tupolev planes are built and modernized in Kazan

        https://sdelanounas.ru/blogs/123269/
        "A map does you no good if you don't know where you are"

        Comment

        • paralay
          Rank 5 Registered User
          • Aug 2005
          • 1418

          Originally posted by LMFS View Post
          Sorry that I was not clear, I was answering to the Su-57 video in the post just above mine
          1.T-50 with engine izd.30
          2. T-50 with engine izd.117
          Attached Files
          Last edited by paralay; 25th August 2019, 04:59.

          Comment

          • LMFS
            Rank 4 Registered User
            • Feb 2018
            • 561

            Okhotnik, with flat nozzle and somewhat changed wing tips:

            https://twitter.com/MuxelAero/status...82462011006980
            Last edited by LMFS; 25th August 2019, 12:01.

            Comment

            • Austin
              Rank 5 Registered User
              • Oct 2003
              • 6506

              Hero of Russia spoke about the Su-57 fighter, which the VKS are proud of

              https://ria.ru/20190825/1557873124.html

              MOSCOW, Aug 25 - RIA News. The Su-57 fighter is the pride of the VKS, it has no analogues in the world, said test pilot, Hero of Russia Yuri Vashchuk in an interview with the weekly Zvezda .

              In addition to the minimum visibility for radars in all wavelengths, including infrared and radar, the aircraft has super maneuverability and the ability to evade enemy attacks at supersonic speed without afterburner. Plus, the aircraft is multifunctional and can solve both the tasks of gaining superiority in air and work on ground and surface targets, "said Vashchuk.

              He added that, in addition, the qualities of Russian pilots should be taken into account, in particular, their decisiveness and desperation, as well as skill.

              If our pilots could show real miracles of heroism on plywood planes during the last war, then imagine what they can do on such a machine! I do not advise anyone to experience the power of the Russian SU-57 in their own skin! - emphasized the pilot.

              Vashchuk also said that work to build up the combat capabilities of the latest fighter still does not stop.
              "A map does you no good if you don't know where you are"

              Comment

              • Austin
                Rank 5 Registered User
                • Oct 2003
                • 6506

                This one again confirms that 117 Engine can supercruise PAK-FA
                "A map does you no good if you don't know where you are"

                Comment

                • LMFS
                  Rank 4 Registered User
                  • Feb 2018
                  • 561

                  Originally posted by paralay View Post
                  1.T-50 with engine izd.30
                  2. T-50 with engine izd.117
                  Thanks paralay, I only had the table with the izd. 30 values for the Su-57 but not those for izd. 117. As usually, I am left wondering where the data come from, apart from attentively following sources and using your drawings, that I by the way consider very accurate and a valid reference. My comments nevertheless:

                  - Su-35 weights 3 tons more than Su-27? Why? The Flanker was a very big plane in not a small part due to old systems technology of the USSR demanding a big airframe. Nowadays this is not the case anymore, as we see in the reduced size of the Su-57 and in the increased fuel capacity of the Su-35 compared to older Flankers. Maybe a good calculation could be done based on known empty weight of older Flankers and publicly available acceleration values of those and Su-35.
                  - Per official data, uninstalled military thrust of izd. 117S is 8800 kgf, that would mean 17600 kgf instead of 17740 as in your table
                  - To the estimation of izd. 30's thrust: ratio with and without afterburner seems improper of a supercruising engine, it keeps the same relation seen on izd. 117S but with increased values. On the one hand, the military thrust seems a bit low considering statements that it will have a higher specific thrust than F119. So, due to similar size to F119, thrust should be also higher, as supported by claims (which I increasingly start to believe) that Su-57 will cruise at ca. 2 M. The maximum thrust seems high, would demand really high airflow for an engine that should have roughly the same diameter than izd. 117 and besides its bypass ratio should be lower than the later. What I would really underline is the intake design that will probably allow for very high installed performance, especially at high altitude due to oversized capture area and variable ramps. The plane is clearly optimized for kinematic performance at high altitude / supersonic flight.

                  Comment

                  • panzerfeist1
                    Rank 6 Registered User
                    • Feb 2018
                    • 413



                    Hmm so I guess the stealth problem in the back will be addessed in the future regarding this mock up design of the SU-70?
                    I thought the fall of western civilization was a tragedy, now I realize it's a comedy.

                    Comment

                    • paralay
                      Rank 5 Registered User
                      • Aug 2005
                      • 1418

                      Originally posted by LMFS View Post
                      - Su-35 weights 3 tons more than Su-27? Why?
                      Su-35S, the volume of electronic equipment has decreased. Its density if I am not mistaken 320 kg/m3. In its place filled with fuel density of 800 kg/m3. Heavier nozzles and engines with increased resource, they are also heavier. Reinforced wing, now there can be suspended external fuel tanks 2 x 2000 liters. This required strengthening the structure, logically.

                      Su-57. The selected angles for the nose cone and air intakes clearly indicate a maximum speed of at least M=2.35 (2500 km/h) The selected angle of the leading edge of the wing implies a high cruising speed, probably M=1.78 (1890 km/h)

                      Comment

                      • panzerfeist1
                        Rank 6 Registered User
                        • Feb 2018
                        • 413

                        thanks lmfs for the guys twitter account. https://twitter.com/MuxelAero/status...16612338868230

                        I hope they have more newer weapons than just those 2.
                        I thought the fall of western civilization was a tragedy, now I realize it's a comedy.

                        Comment

                        • LMFS
                          Rank 4 Registered User
                          • Feb 2018
                          • 561

                          Originally posted by paralay View Post
                          Su-35S, the volume of electronic equipment has decreased. Its density if I am not mistaken 320 kg/m3. In its place filled with fuel density of 800 kg/m3.
                          I am referring to empty weight, which in your table is 19,300 kg. I need to check in detail, but Su-27 was less than 17 tons if don't remember wrong.
                          Heavier nozzles and engines with increased resource, they are also heavier.
                          According to Rosoboronexport, the Al-41F1S is 84 kg heavier, so 168 kg difference, you are right. AL-41F1 is supposedly lighter, 150 kg less than AL-31F.

                          Reinforced wing, now there can be suspended external fuel tanks 2 x 2000 liters. This required strengthening the structure, logically.
                          True, this may be a major contributor but I assume modern production and materials should help increase the resistance of the structure with little weight increase. If not, all the progress in the engines would be negated by the increase in empty weight and Sukhoi would fail to improve the kinematic behaviour of the plane.
                          Su-57. The selected angles for the nose cone and air intakes clearly indicate a maximum speed of at least M=2.35 (2500 km/h) The selected angle of the leading edge of the wing implies a high cruising speed, probably M=1.78 (1890 km/h)
                          I tend to agree and would stretch those figures even a bit further. Latest data I saw which seemed half reliable (a supposed expert whose article I need to dig up) indicated cruise speed 2 M, max speed 2.45 M (2600 km/h). Few months before I would have thought this to be far fetched, now after reading Marchukov and the patent I tend to think it is actually realistic:

                          - No reason for 15 years of delay to create a weapon against F-22 which is clearly inferior from the beginning. F-22 can supposedly cruise at 1.82 M, max speed is 2.25 M IIRC
                          - Izd. 30 is stated as being the engine with highest specific thrust in its category available anywhere.
                          - Supercruising performance is one of the main design focus of the plane, as stated in the patent and obvious from many design traits.
                          - It makes no sense to incur the effort and expense of designing a variable intake which is only better above 2 M (as stated in the very patent) if your maximum speed is not substantially higher than that.
                          - F-15 is still very much in service and will continue to do so for the foreseeable future. Its max. speed is 2.5 M, so it makes sense for Su-57 to be at that level too, in order to dominate the engagements with superior range and markedly better cruising speed / acceleration.

                          USAF's best chance IMO is to bring AETP engines to the F-22/ F-15 / F-35 fleet, in order to counter the more than probable advantage in kinematics of the Su-57.

                          Comment

                          • paralay
                            Rank 5 Registered User
                            • Aug 2005
                            • 1418

                            Su-27 early series had an empty weight 16380 kg. Later series, including Su-27SK - 17500 kg

                            Comment

                            • LMFS
                              Rank 4 Registered User
                              • Feb 2018
                              • 561

                              Originally posted by panzerfeist1 View Post
                              Hmm so I guess the stealth problem in the back will be addessed in the future regarding this mock up design of the SU-70?
                              Indeed it looks like this is the plan. Coherent with the design of a stealthy, subsonic deep strike and intelligence platform that cannot rely on kinematics to defeat air defence.

                              Originally posted by paralay
                              Su-27 early series had an empty weight 16380 kg. Later series, including Su-27SK - 17500 kg
                              Ok thanks, I will research a bit on that

                              Comment

                              • panzerfeist1
                                Rank 6 Registered User
                                • Feb 2018
                                • 413

                                Damn not even the MAKS airshow has started and we are getting information like this https://twitter.com/KomissarWhipla/s...10972661252097 an IL-76 using scramjet missiles.

                                I am hoping for something more grandiose like an internal scramjet missile placement for an SU-57, KRET showcasing FICs based jammers or radars, avionics layout of the okhotnik, showcase mockup model of a mig-41, etc etc. The last airshow seemed boring I hope it wont be the case for this one.
                                I thought the fall of western civilization was a tragedy, now I realize it's a comedy.

                                Comment

                                • JSR
                                  JSR
                                  Rank 5 Registered User
                                  • Aug 2011
                                  • 4982

                                  Su-27SK weight is about 16.8 tons. range with 9.4 tons fuel and 4AAM 3530 km.
                                  http://www.sukhoi.org/products/earlier/251/

                                  Comment

                                  • paralay
                                    Rank 5 Registered User
                                    • Aug 2005
                                    • 1418

                                    Su-27SK (flight manual)
                                    27380 kg - 9220 kg (fuel) - 726 kg (2R27+2R73) - 100 kg (pilot) - 58 kg (shells) = 17276 kg
                                    23250 kg - 5090 kg (fuel) - 726 kg (2R27+2R73) - 100 kg (pilot) - 58 kg (shells) = 17276 kg

                                    not taken into account the links of the tape GSH-301
                                    Attached Files

                                    Comment

                                    • Scorpion82
                                      Rank 5 Registered User
                                      • Jul 2005
                                      • 4482

                                      Originally posted by paralay View Post
                                      Su-27SK (flight manual)
                                      27380 kg - 9220 kg (fuel) - 726 kg (2R27+2R73) - 100 kg (pilot) - 58 kg (shells) = 17276 kg
                                      23250 kg - 5090 kg (fuel) - 726 kg (2R27+2R73) - 100 kg (pilot) - 58 kg (shells) = 17276 kg

                                      not taken into account the links of the tape GSH-301
                                      Not taken into account appear to be the pylons, unusable fuel and consumables incl. hydraulic fluid, lubricating oil and chaff/flare rounds for loaded dispensers.

                                      Comment

                                      • paralay
                                        Rank 5 Registered User
                                        • Aug 2005
                                        • 1418

                                        fuel 9400 kg - 9220 kg = 180 kg
                                        2 APU-410 + 2 P-72 = 2 * 70 kg + 2 * 49 kg = 140 kg + 98 kg = 238 kg
                                        96 traps (thick fins) * 1 kg = 96 kg

                                        17276 kg - 180 kg - 238 kg - 96 kg = 16762 kg

                                        Comment

                                        • LMFS
                                          Rank 4 Registered User
                                          • Feb 2018
                                          • 561

                                          Originally posted by Austin View Post
                                          This one again confirms that 117 Engine can supercruise PAK-FA
                                          It is unclear if they refer to Su-57 with current engines or not...

                                          In any case it is not the same to "supercruise" at 1.8 or 2 M than barely maintaining M > 1 for some minutes. The first has a clear tactical value, the later, not really. We don't know what the izd. 117 allows to do. The designers said that it fulfilled the MoD requirements, but clearly an engine as izd. 30 (designed for supercruise) should improve over that by a big margin, so what were the original requirements? Was there a "nice to have" requirement that latter evolved into a "must", as the progress with the design of the izd. 30 allowed for more ambitious goals? IMHO and all that being considered, the Su-57 with the current engine maybe cruises at 1.2 - 1.3 M, maybe 1.5 M being very optimistic, with the second stage engines should be close to 2 M.

                                          Comment

                                          Unconfigured Ad Widget

                                          Collapse

                                           

                                          Working...
                                          X