Source: Vancouver's fish
Every time I read the comments of readers, it is a kind of enjoyment. It can inspire a lot of great views and thinking, which is very inspiring to me. For example, a reader asks what is the point of pouting on the ground and raising your head in flight?
This question is a good question, I haven't really thought about it. Comparing the attitude of Su-57 on the ground and in the air, the lower front fuselage can shorten the height of the nose landing gear pillars, bringing a series of benefits such as saving structural weight, reducing the size of the nose landing gear compartment, and increasing the effective volume. Although the ground posture is a bit ugly, the jet of the engine is still on the horizontal plane after flying into the air, otherwise it will be difficult to control the flying posture because of the loss of thrust. The raised nose can also generate a certain lift on the bottom of the front fuselage. As for the thrust loss caused by the eight-shaped camber layout, the angle is not large, and the vector nozzle is likely to be corrected. As long as the engine thrust is sufficient, it is not a big problem.
Yesterday, I watched a few official Sukhoi Su-57 videos. The most impressive thing is the full-motion vertical tail movement that I mentioned in the previous article. I remember that many years ago when I saw the F-16CCV on-control layout verification machine, I found it very incredible. With the addition of two full-moving vertical canards, it was possible to perform precise maneuvers without changing the flight attitude.
and today's Su-57 can do this with its full-motion vertical tail. The formation flight mainly relies on the vertical tail for automatic adjustment of fly-by-wire control, and the deflection range of the flat tail and aileron. They are all very small, and they can quickly change their posture with the nose pointing unchanged, and fly as light as a fallen leaf.
> Video tubing address: https://www.youtube.com/watch?v=jsYczZC_gqs
Falling leaves, hammerhead maneuvering and even nose It’s easy to circulate the center of the circle. Compared with the F-10CTV verification aircraft at the Zhuhai Air Show, the vector nozzles, canards, and ailerons are deflected to the extreme (see F-10B and TVC (below)). Amazing mobility not commensurate with the large body.
J-20 happily turning its differential canard wings and hanging tails, smiling without saying:
I found a copy of "Fighter Concept Design" on the Internet The open paper of "Integrated Analysis of Aerodynamic Characteristics with Stealth" was jointly written by Beihang University, Naval University of Aeronautics and Astronautics, and Naval Aviation Institute in 2016. The three-dimensional digital model simulation test was carried out on the prototype of Su-57. The following figure shows the upper and lower surfaces of the simulator Pressure division:
The more reddish area in the figure, the greater the aerodynamic pressure, and the more blue the lower the pressure. It can be seen that only the nose of the upper surface has a higher pressure, which has the effect of restraining the upward tilt. This may be the effect of the special shape of the radome mentioned in the previous article. The movable side strips in front of the air inlet on the lower surface and the side area of the fuselage are the parts with the largest aerodynamic pressure, indicating that the pre-compression effect in front of the air inlet is obvious, and the leading edge of the side bars can generate a lot of lift. The pressure distribution of the rear fuselage, main wing, and flat tail is very uniform, including the tail cone, which contributes a certain amount of lift, and the lift body fuselage is well designed.
By the way, although the United States does not like to use canards more than Russia, the research on canards and follow-up layout is quite in-depth, except for F-15 ACTIVE, F-16 AFTI, even F-4 There is a little-known F-4E CCV canard-wing fly-by-wire verification machine.
Weapon System
Another major controversy of the Su-57 is the bomb bay, whether there is a side bomb bay, whether it can be opened for smooth launch of weapons, and whether the depth affects the strength of the body All have caused long-term controversy online. Even recently, some netizens told me that they talked about the side bomb bay of the Su-57 on the forum and were ridiculed by the crowd.
I really don’t know what caused so many people to look down on Russian aircraft designers so much. Is it because the news is too blocked? Back in 2015Russia’s semi-official website has already released the layout of the weapon system, including a 30mm cannon on the right side of the cockpit, two main bomb bays positioned longitudinally in the belly, and side bombs in the shape-preserving cocoon outside the air intake. Cabin and 6 external hanging points.
Machine Gun
GSh-30-1 30mm cannon is the standard configuration of the Su-27/MiG-29 series, and it is also the heaviest among the world’s active guns of the same caliber. The lighter one weighs only 46 kg, has a rate of fire of 1500 rounds per minute, and has 150 rounds of ammunition.
> The GSh-30-1 aircraft gun used for ground shooting test. This is only a front fuselage model, so it looks very crude.
Because GSh-30-1 is a single tube, It occupies a very small space. The muzzle device of Su-57 is just a small fairing. The front half is a metallic semi-cone, and the muzzle is exposed after flipping (the shape is similar to the flipping fuel cap on the back of the B-2) . Although this design protrudes from the surface of the fuselage compared with the flip-up muzzle cover of the F-22 and F-35, the stealth is reduced, but the gun reaction speed is faster, the exposure degree when firing is smaller, and the aerodynamics is almost No effect.
F-22’s M61A1 Vulcan Gatling gun has a caliber of 20 mm, has 480 rounds of ammunition, has a weight of 112.5 kg, and a rate of fire of 6000 rounds per minute. The six-barrel muzzle has a large diameter. If the open design is adopted, it will cause a lot of losses in terms of resistance and stealth. Therefore, a flip muzzle with better stealth performance when not shooting is used.
> The F-22 muzzle cover plate opened during the test flight
main bomb compartment
Su-57 almost arranged between the two engine nacelles in the belly Two large tandem main bomb bays of equal length, each measuring about 4.6 meters x 1 meter, and the depth is unknown (estimated to be about 0.7 meters); the main bomb bay of F-22 is 3.9 meters x 2 meters, and the depth is less than 0.4 meters .
It is no longer a problem whether the main bomb bay is available, but doubts have always existed, mainly in two aspects: First, the bomb bay is just due to the negative effect of the tunnel after the bomb bay door is opened. The nip, whether the weapon can be separated smoothly; the second is how deep the bomb bay of such a thin fuselage can be. The corresponding position of the Su-27 is just the main beam and fuel tank. After the built-in bomb bay is dug, the strength of the body is affected.
Lao Maozi has been studying the aerodynamic configuration of Su-27/MiG-29 for more than 40 years. Who knows the aerodynamic pressure and structural strength of the twin-engine tunnel better than themselves? From the flight video of the Su-57, it can be seen that there is no difficulty in flying various high-G maneuvers like clouds and flowing water, and the strength of the body structure really does not need to worry about them.
In fact, there is a considerable gap between the front and rear main bomb bays, and it is impossible to connect them into a long strip. This interval can be strengthened horizontally, and there is more space available in the vertical direction. The fact that Su-57 and Su-27 look alike does not mean that their internal structures are exactly the same. Designing fighter jets and modern warfare are both very rigorous sciences. It's not a joke that you can't just look at the photos.
even includes the gaps in the main bomb hatch that can be squeezed into the fingers that were widely criticized at the air show. From another angle and light, it is only a V-shaped groove, which may affect the structural strength and sealing of the hatch. Sex or the aerodynamics of opening and closing.
No proof, let’s take a look at Sukhoi’s specific measures. On the F-22 and F-20, in order to allow the ammunition to pass through the boundary layer and leave the main bomb bay smoothly at supersonic speeds, hydraulic ejection launchers are specially designed. No diamonds, no porcelain, the famous Russian air-to-air missile development unit-Pennant Machinery Manufacturing and Design Bureau displayed two types of vertical ejection racks specifically for Su-57 on its 70th anniversary: UVKU-50L for mounting For weapons within 300 kg, the UVKU-50U can carry more than 700 kg.
them and belowThe standard R-77 pylon of the Su-27/Mig-29 series is obviously different. There is no rectifying structure at the front and rear ends, and it is only suitable for the built-in bomb bay. The pylon is very compact, and the X-shaped folding mechanism is hydraulically operated. The tube is pushed out. This shows that Russia has carefully developed a new launcher dedicated to stealth fighters for the Su-57.
> UVKU-50L hanger structure diagram
> F-22's LAU-142/A vertical ejection hanger has V-shaped folding joints at both ends, The structure is completely different
Also on display are three air-to-air missiles developed by the Pennant Design Bureau. Except for the R-77 and R-73 below, the top one has never been seen before. The new type of air-to-air missile may be Izdeliye-300. The length of the protective cover is only about 2.35 meters, which is shorter than the R-73 and Sidewinder fighting bombs. The bullet diameter is the same as the R-77, reaching 200 mm; the same The foldable grid rudder is used, and there is a miniature pulse solid rocket motor on the R-77M in the middle of the missile body, which can accurately adjust the flight trajectory; the huge warhead is probably also equipped with a phased array radar guide for R-77M. Lead.
This is a bit like the "Peregrine-Peregrine" medium-range air-to-air missile being developed by the United States. It has a length of 1.83 meters and a weight of 68 kg (AIM-120 is 3.7 meters long and weighs 152 kg). Short "standard" missiles can double the capacity of F-22 and F-35.
> F-22's "Peregrine" missile mounting plan imagined
Foreign military fans have made a schematic diagram of the mounting of the new Russian missile. Su-57 has a bomb bay. With 8 bombs, the total ammunition carrying capacity reaches 16, which is more than the 12 Peregrine Falcons mounted on the F-22. The firepower is very powerful when dealing with medium and short range targets. This also shows that Russia has carefully studied special new missiles for the Su-57.
> Looking down, the left side is R-77M, only one can be mounted, and the right side is 4 new missiles
> side view, bomb bay depth The accuracy of
side bomb bay
is more controversial than the main bomb bay on the Su-57 side bomb bay. The main reason is that its location is so unconventional that many people can’t accept it-2 canoes The type of conformal pod is almost half a meter away from the air inlet, which is unheard of in fighter design.
From the perspective of stealth, any accessory structure that protrudes from the surface of the body is unfavorable, but a closer look at the lower surface of the Su-57 shows that the two pods have at least 4 One function:
Carrying combat missiles: this position is far away from the fuselage, the flow field is relatively clean, and there is less air flow disturbance when the missile is launched. The specific method of opening the hatch has never been disclosed. It remains to be seen whether the two hatches are opened with the UVKU-50L pylon that stretched out above, or the slide rails are turned up on the outer hatch.
Installation of conformal photoelectric detection equipment: Although not installed on several prototypes, it can already be seen at the exhibition that a 101KS-P forward-looking infrared detector is planned to be installed at the front of the cocoon bag to assist low-altitude/night flight And landing, this position has a wide field of vision and has no effect on aerodynamics. > The 101KS-P detector on the left has the same shape as the head of the cocoon bag
rectification + increase: 2 long cocoon bags can be seen as two large wing knives, and move the movable broadside bar below and from The flocculent flow overflowing from the intake duct is constrained on the inside of the side strips, creating a clean flow field for the main wing; at the same time, it also acts as a vertical stabilizer, which further reduces the area of the full-moving vertical tail; the streamlined cocoon itself can also produce Lift (the cocoon bag in the above three-dimensional model is too long and narrow and the shape is not accurate).
Blocking: The engine nacelle and even the entire body of Su-57 are already very flat. While ensuring the fusion of the upper surface wing body, the transition between the nacelle and the canard can not be too smooth, otherwise wideToo much resistance increases too much, so the outer wall of the engine nacelle is almost vertical, forming a strong corner reflector, coupled with the huge gap between the boundary layer partition and the intake and exhaust bypass system, the air inlet The radar reflections on the front and sides are quite strong. The pod with a length of more than 5 meters just occludes this area from the side, and is similar to the widely criticized J-20 ventral fin. It has a good occlusion effect and eliminates a considerable area of right-angle reflection sources. > From this angle, the occlusion effect of the pod can be clearly seen. The camera system pod
mounted on the left side is dedicated to recording weapon separation tests. In view of the special aerodynamic layout of the Su-57, the fuselage has Can't find a place to place two side bomb bays with a large volume. Sukhoi's magical trick not only solves the problem of carrying fighting bombs, but also has considerable side benefits. It is definitely not a failure.
External hanging points
There are 6 hanging points under the wing and the bottom of the nacelle of the Su-57, which can mount auxiliary fuel tanks, large weapons that cannot be placed in the main bomb bay, or special mission pods during non-stealth missions , This is now the main way we see Su-57 carrying ammunition.
Weapon Configuration
The maximum ammunition capacity of Su-57 reaches 8 tons, and the types of weapons that can be carried are very rich, especially large ammunition, which is far more flexible in combat. Super F-22 and F-35, the following picture is the rendering of the airborne weapon produced in 2015:
[ Air-to-air]
Izdeliye 810 ultra-long-range missile-length 4.2 Meters, weight 600 kg, range 400 kilometers
K-77M medium-range missile-projectile length 3.7 meters, weight 190 kg, range 110 kilometers
K-74M2 combat missile-projectile length 2.9 meters, weight 105 kg , A range of 40 kilometers
[air-to-ground]
Kh-38M modular infrared thermal imaging air-to-surface missile-projectile length 4.2 meters, weight 520 kg, range 40 kilometers
Kh-35UE Ship missile-projectile length 3.8 meters, weight 520 kg, range 260 kilometers
Kh-58UShKE high-speed anti-radiation missile-projectile length 4.19 meters, weight 650 kg, range 245 kilometers
[ guided bomb]
KAB-250/500/1500-The weight is 250kg/520kg/1525kg respectively
[External weapon]
BrahMos-NG supersonic ram-powered cruise missile-bullet length is 5 meters, It weighs 1.5 tons and has a range of 290 kilometers.
Kh-31AD/PD supersonic anti-ship missile-with a length of 5.43 meters, a weight of 715 kilograms, and a range of 160 kilometers. The Kh-59MK2 subsonic stealth cruise missile, which has been put into actual combat, has a length of 4.2 meters, a weight of 770 kg and a range of 550 kilometers.
> On May 5, 2018, Russian Defense Minister Shoigu disclosed the video of the Su-57 launching the KH-59MK2 stealth cruise missile test. The red test bomb flashed from the belly of the plane, explaining Not a plug-in.
Russia even plans to equip Su-57 with Kh-47M2 "dagger" hypersonic air-launched ballistic missiles. Previously it was carried by MiG-31K and Tu-22M3. The range launched by MiG-31K is 2000 kilometers, the "Backfire" launch can reach 3000 kilometers, the flying speed is 10-12 Mach, the warhead weight is 500 kilograms, and nuclear is always available. , Is a powerful quasi-strategic weapon.
> This is a computer-simulated "dagger" mount image
Seeing this, you may have questions, Su-57 mountWhat are the uses of so many large weapons?
At the beginning of the 21st century, the Russian Air Force proposed five plans for the future aviation force: PAK DA Future Long-range Aviation System, PAK TA Future Transport Aviation System, PAK DP Future Intercept Aviation System, "Vespa EP" Future Attack Aviation System and PAK FA Future Frontline fighter system.
> PAK DA-stealth strategic bombing
> PAK TA-Il-106 supersonic strategic transport aircraft, planned to carry 200 tons, can transport 4 A supersonic strategic transport aircraft of the "Amata" tank! The current load index has been lowered to 120 tons.
> PAK DP-MiG-41 stealth interceptor
But with the sudden decline of Russia’s national power, only PAK FA hatched the Su-57, other sci-fi plans or It ends without a disease, or it may be delayed until after 2030. Under such circumstances, the Su-57, which was originally used to replace the Su-27 and MiG-29, and was only responsible for air superiority combat missions, became the only stealth manned combat platform in the hands of the Russian Air Force. This single seedling was naturally given more With multiple capabilities, it can carry the largest possible ammunition in a stealth configuration, and can perform different missions such as long-range interception, ground/anti-ship attacks when necessary.
The design of the entire Su-57 can be said to revolve around these two large main bomb bays. The length should be long enough to mount a cruise missile of the Kh-59MK2 level, and it inherits the Su-57. The layout of 27 flat lift body fuselage and wide-spacing engines (of course, Sukhoi’s best aerodynamic tradition must be carried forward, and if the stove is restarted, only a few other PAKs will end up), and a horizontally arranged bomb bay like F-22 It can't be realized, it can only be placed vertically in the tunnel. Even with the smallest cross-section of the bomb bay, the tunnel of the Su-57 is still wider than that of the Su-27. In addition, the wide inlet required by the engine with larger air intake and the need for lift for supersonic maneuverability, In the end, it became the "Su-27".
can't help but think of the J-20, its bomb bay is actually almost the same length as the Su-57, and the width is even larger (I will not measure the specific values), and it is arranged side by side. , Then the types of ammunition and combat capabilities it can mount also have a lot of room for imagination.
aviation
I don’t want to talk about Su-57's avionics any more, but the J-20-[6] Avionics system (below) has already been mentioned in the article, and to There has not been much change so far. The only thing that is wrong is that China has developed its own side-viewing radar system, which is said to have adopted both the J-20 and Xiaolong Block3. However, I have only seen the KLJ-7A model used by the "Fierce Dragon". Two large side-viewing radar arrays are indeed installed on the side, while the active J-20 is not seen on both sides of the nose. Signs of antenna array.
According to the current level of Russia’s electronics industry, Su-57’s avionics is indeed not advanced. Most of the equipment and functions have been transferred to Su-35, which is similar to the gusts and typhoons. The only highlight of the fourth-generation semi-level is the two side-view phased array radars. Lack of the EODAS system on F-35 and J-20, especially the powerful background data fusion and processing capabilities, two more side-view radars are of great significance to Su-57, at least to ensure that the front hemisphere is more complete The situation awareness and multi-target combat ability. In addition to the small rear-view radar in the tail cone, a mature radar system is used to replace the much more demanding photoelectric system to achieve panoramic coverage. The difficulty of research and development and the cost of procurement are greatly reduced. Of course, the price is not stealthy, and it needs to radiate outward. Electromagnetic waves.
