【Military Subplane】Author: Lele
With the suspected J-35 test flight, the picture of the tail nozzle appearing circulated, and the domestic medium thrust engine surged to the forefront again. Based on the smooth development of the domestic turbofan-10 and even the turbofan-15, the outside world is generally very optimistic about the future of the domestic turbofan, and even rumors of the installation of the advanced turbofan-19 in the first two years, but the truth is not so simple.
▲As early as the FC-31 era, it was the focus because of the "black smoke".
Thanks to the technical support provided by the Soviet Union, the development of turbojet engines in China in the early years was relatively smooth. However, it was not until the 70s that the "Spey" engine was purchased from the United Kingdom at a high price, and it was not officially stepped into the field of turbofans. By the way, the design / manufacturing materials of modern large-scale equipment are calculated by the ton, and the full set of transportation can only be carried out by car or airplane (for example, Russia provides Su-27SK manufacturing materials, that is, it is transported by Il-76), and it is impossible in any country to obtain one or two parts/materials to solve the problem of advanced engines. Therefore, although many samples of turbofan engines were obtained in China at that time, they eventually started from the imitation of "Spey". What is embarrassing is that at that time, the engine had to be used as a fighter supporting project in order to get development resources, and the imitation "Spey" had no equipment object for a while, so it was refrigerated for many years after the initial completion of the imitation.
▲The turbofan-9 carried by the J-7 series is the origin
It was not until the J-7 was clearly powered by the imitation "Spey", that is, the later turbofan-9, that the follow-up development process was accelerated, but the lack of preparation and technical difficulty caused the turbofan-9 to lag far behind the project schedule. Until 1998, when the design of the J-7 was finalized, the turbofan-9 still could not be mass-produced, and China had no choice but to go to the UK to buy the original "Spey" that was decommissioned and mothballed. After 2007, the turbofan-9 was available, and the domestic version of the turbofan-9 was equipped with more than 200 aircraft. The two major problems of imperfect R&D system and serious lack of technical reserves are vividly demonstrated in the turbofan-9. The technology of the British 70s still needs to take many years to master at the beginning of this century, which is also a true portrayal of the strength of domestic aviation in that era.
▲Today, the turbofan-9 continues to play a role
Fortunately, the thrilling research and development process of the turbofan-9 is only once, and the development of domestic after-life development has basically avoided these big pits. However, the technology of turbofan-9 itself has limited gain for the subsequent development of domestic aviation development, so AVIC made a very bold choice at that time - turbofan-10. During the Cold War, the United States and the Soviet Union took the lead in conquering the third-generation large-scale push technology, and they also paid a huge price for it. After the end of the Cold War, there were many countries that developed third-generation aircraft, but most of them did not dare to touch the big push because of the lessons of the United States and the Soviet Union, and China was the only special case. In the context of the European "Typhoon" and "Rafale" have carried two medium pushers to avoid the technical threshold, the turbofan-10 means great courage and perseverance.
▲The double-engine mid-push "Typhoon" avoids the technical threshold of the big push
Of course, the development of the turbofan-10 was indeed extremely difficult, and the twists and turns of the process were beyond the ups and downs, but fortunately, it survived in the end. When the turbofan-10B is mounted on the J-10C, and the performance is recognized by the Air Force, the domestic aviation engine can boldly say that it ranks third in the world, and the follow-up pre-research and development of the turbofan-15 will naturally be pushed down the river. Unlike the previous generation of turbofan-10 packs, in the era of stealth fighters, China chooses the coexistence of twin-engine high-thrust heavy aircraft and twin-engine medium-sized thrust aircraft. Technically, this is more conducive to the technical upgrading of medium-sized aircraft in the later stage, and it is also in line with the trend of gradual increase in the weight of stealth fighters, but the middle push is an area that China has not set foot in before.
▲The significance of the turbofan-10 cannot be overpraised
Theoretically speaking, since the big push can be completed, the middle push is not a problem, but the reality is never something that can be solved by theory. Even now, the resources for the development of advanced engines are extremely limited. It is impossible for the turbofan-19 to preempt the turbofan-15 in the early stage, so even if the technology is not a problem in theory, the progress will be greatly delayed. At this stage and even in a few years, the J-35 can only use transitional push. It's just that from the perspective of the technical route, the J-35 power in early mass production is most likely to have been iterated many times, and there is no longer the shadow turbofan-21 of the RD-93. It's like the development of turbofan-10 to the end, and only domestic elements remain. In other words, although the outside world is looking forward to the J-35 carrying the turbofan-19, the reality is that the turbofan-15 will inevitably occupy a lot of resources, and only after it is basically formed, the turbofan-19 will have a chance to take the center stage.
▲Matching with the J-20 means that the status of the turbofan-15 cannot be shaken
Therefore, although the glorious days of the J-35 can be predicted, there is a high probability that it will continue to use transition power in the early stage of its service. Whether it is a pure imitation of the RD-93 modified turbofan-13, or an upgrade on the basis of the turbofan-13, the legendary third-generation aviation engine top turbofan-21 will directly determine the performance of the early J-35. Of course, the altitude reached by the J-35 in the end is determined by the development of the turbofan-19. Different from the anxiety of the J-20A carrying AL-31F in the early years, now the country can afford to wait, and it is necessary to avoid rushing forward.