Chapter 1244 The core craft of J-8E

What's more, the headquarters clearly stated in the letter of intent for bidding for multi-purpose fighters that improvements should be made on the basis of mature and old models so that the troops can reduce maintenance costs while quickly forming combat capabilities.

Northeast Airlines finally won the J-8 improvement project and replaced it with JJ-7MAX. This is not a raw talk to the headquarters. We just put your words on the ears. Some things can be done, but it’s not good to say it. At the very least, the face of the headquarters still needs to be taken care of.

Therefore, based on the body of the J-8II fighter, it is enough to change the wing, air intake and integrated avionics system. After all, it is only a transitional combat aircraft, and it is very likely to become a foreign trade model for full-time export in the future. Too harsh.

  If it becomes complicated and cannot achieve rapid mass production and rapid assembly, if it takes a few years to drag it, the 10th project can be finalized by then, and the Su-27 assembled with Russian imported parts will be completely rolled out.

The   J-8E, the so-called transitional combat aircraft, was directly rubbed on the ground by the combination of the weight and weight of the two heights before the transition.

Therefore, whether the J-8E is an improved version of the J-8II fighter or the alternative rebirth of the J-7MAX, the most important thing is to target the domestic second-generation and third-generation aircraft. It is efficient and fast. Plug in and make a wave.

   So it is required that this model must use mature technology from the inside to the outside, so that it can be quickly finalized, quickly mass-produced, and equipped in batches, and the empty window period is full.

Needless to say, a series of subsystems such as DSI inlet, side strip wing and swept wing airfoil structure, and integrated avionics system, etc. Ascendas Group has been cultivating the JJ-7MAX for several years, and it has been verified in Real Dragon. Repeated verification on board,

  As for technology and production, Ascendas has already prepared several sets of plans.

  Don’t say anything else, the reason why the engine uses WD-58MVP instead of the more advanced WD-60 series is because WD-58MVP is more mature and mass production is not difficult.

  The more powerful WD-62MPV is indeed very good. However, although this aero engine with a 2.5-generation core engine is no problem in production, it has a very long production cycle due to high technical requirements and a serious shortage of production capacity.

  While WD-58MVP is a typical medium thrust engine, the thrust-to-weight ratio of 7.5 can be described as quite satisfactory, and the core engine is the second-generation core engine with higher maturity.

  Although the performance is not very prominent, but the advantage is that the production cycle is short, the production cost is low, the production can be quickly put into production, and it is independent and controllable.

Of course, on the basis of the overall maturity of the J-8E multi-role fighter, it is not without new technical applications. For example, metal additive manufacturing technology. The main structural frame of the J-8E fighter body is the NB-985Plus developed by China Ascendas. Produced by a metal 3D printer.

"Of course, we still encounter many problems in some key production areas..." After introducing the J-8E multi-role fighter in general, Zhuang Jianye's conversation suddenly changed: "After all, the multi-role fighter is the same as the previous high-altitude high-speed combat aircraft. Two different combat concepts.

   Therefore, shortening the fuselage is an inevitable choice. The problem is that the shortening of the fuselage brings a very serious problem, that is, the structural center of gravity is broken, so it is easy to cause the aircraft to stall in the air.

Although we adopt a statically unstable design and cooperate with the fly-by-wire control system to completely solve this problem, at this stage, the fly-by-wire control system of this system is still being developed and tested, and it is difficult to implement it in a short period of time. What we use on the J-8E is still a traditional mechanical control system, so the problem of the center of gravity is an important difficulty we have to face..."

On this issue, Zhuang Jianye said in great detail, and the military leaders naturally nodded slightly when he heard this statement. Zhuang Jianye was right. Although the fly-by-wire control system is a good thing, the development cycle of an aircraft by fly-by-wire is the least. It will take eight years.

  After all, the compilation of the entire system must cover all the conditions of the aircraft in all states. The light test is a very complicated and voluminous task, and it is not accomplished overnight.

   Therefore, in the reported indicators of the F-8E, although the fly-by-wire control system is covered, it is only used as a later improved development model.

  Therefore, the center of gravity of the aircraft is a big problem. Regardless of the length of the body that has been shortened by only 3 meters, the impact is indeed global.

Because of this, the airframe has to add counterweights in some places to offset the cut 3 meters with counterweights; or in the remaining airframe, further reduce the structural weight, so that the remaining airframe can reach a new balance again. .

It is not impossible for aircraft to increase counterweights, but it depends on the purpose of these counterweights. Needless to say, if it is to increase the ammunition load or fuel load, these counterweights that help enhance the aircraft's continuous combat capability are of course beneficial. Is unnecessary.

With the body space of the J-8, it is basically impossible to increase the beneficial load. If not, the wingspan of the J-8E multi-role fighter will not reach the value of 8.6 meters. In addition to improving the overall lift, the most important thing is A large overall fuel tank can be installed inside the wing to increase the fuel capacity and enhance the continuous combat capability of the J-8E multi-role fighter.

  Since the counterweight method cannot work, the only way to reduce the structural weight is to reduce the weight of the structure.

This brings about a problem. If you want to reduce the weight of the structure, you need to use new materials and new processes. The long-term experiments and verifications brought about by this will inevitably slow down the development progress, and then make the excessive models into obsolete models. Some of the gains are not worth the loss.

  What's more, the cost of new materials and new processes is also very high, which also does not meet the low-cost and high-efficiency requirements of the headquarters.

  Based on the above, it is necessary to subtract under the original frame of the J-8II fighter.

  The material does not move, the basic structure does not move, and subtraction needs to be done. This difficulty is not generally high.

  "Fortunately, we have the NB-985Plus metal 3D printer, which realizes the one-time forming production process of large titanium alloy structural parts, and the overall performance is basically the same as that of similar foreign high-precision forgings. UU看书www.uukanshu.com

  So we can use the NB-985Plus metal 3D printer to produce the original 32 titanium alloy structural frames of the J-8II fighter with a length of 4.2 meters and a height of 1.6 meters.

Due to the precise control of the material and the elimination of the welding process, the 32 titanium alloy metal frames have a total weight reduction of 450 kg. Together with the two WD-turbofan engines, the weight reduction is 480 kg, which basically meets the requirements for rebalancing the center of gravity. . "

Having said this, Zhuang Jianye paused and looked at the technical leaders including senior researchers with undiminished smile, and the voice rang out again without a rush: "So...Leaders, if you want to ask us NB-985Plus I really can’t say about the application of metal 3D printers.

After all, the J-8E has just rolled off the assembly line and the flight experiment has not been carried out yet. I’m not too early to come to a conclusion. Anyway, the J-8E is here now, so don’t bother a few leaders to take a look and see what else we have. Whatever you have done wrong, please don’t take care of face. You should criticize and criticize, you should make corrections. After all, the core craftsmanship of the J-8E is all on this..."

  As soon as these words came out, the technical leaders of the research team who were like the face of Sichuan Opera were so embarrassed that they were extremely ugly, looking at the domineering J-8E for a long time, so they couldn't say a word!

  (End of this chapter)