For composite materials, this thing is still the kind of hurdle that cannot be bypassed in the aerospace field, if it is said that in the previous weight reduction requirements of the aircraft body, aluminum-lithium alloy can also be used to achieve, then in the manufacture of aero engine duct casing, this is destined to be manufactured only by composite materials.

Military afterburner engines use composite materials to manufacture ducted casings, this technology was first used when General Motors improved the F-404 engine, and then began to be put into large-scale use in aero engines in Western countries, and since then various new military afterburner aero engines have come over in this way.

Previously, because the technology of the Republic was not enough, the turbofan 12 still used a steel metal casing, and the new generation of high-thrust military turbofan engines required greater thrust and higher thrust-to-weight ratios, and the composite casing still had to be faced after all.

But overall it is quite good, at least now there are some domestic research and use of composite materials, although only the basic aircraft body, the use of blades, but after all, the country has begun to study this aspect, the most basic fiber material is a finished product, and the research on the composite casing used on the aero engine can also begin.

Yang Hui is the first united front to vigorously develop composite materials for this time: "The research of composite materials is indeed necessary, to be able to manufacture composite casings for military engines, which also means that we can manufacture super-large bypass ratio of civil turbofan engine bypass fan fan containment ring, the diameter of that thing is indeed too large, the cost of traditional metal processing and manufacturing is too high, and the weight is not easy to control. Therefore, there is still a lot of room for development of composite technology. ”

Fan containment ring, in fact, this thing is the outer duct casing lining of the fan of the turbofan engine with a large bypass ratio, but in order to highlight the huge size of this thing, and can be distinguished from the casing, it is called the containment ring, but in general, these two can be counted as one thing.

Of course, Master Wen knows this truth better than Yang Hui, not only clearly, but even more so. No, after taking Yang Hui's words, he began to preach other benefits.

"Similarly, I am the chief designer of the CG-2000 engine, which is the most advanced engine in the field of civil large-bypass ratio turbofan engines, so I can say that I know all the weaknesses in the domestic large-bypass ratio turbofan engines, the reason why I propose to vigorously develop composite material technology this time is that the application of composite materials in the field of aero engines is not only the ducted casing, we want to manufacture larger diameter fans in the future, and the blades made of composite materials are our only way out."

Yang Hui knows the reason why Mr. Wen said this, because the fan blades made of composite materials are indeed too good for weight loss, and the prospects are bright. Although Rolls-Royce's honeycomb hollow titanium alloy blades are also a path, even in the previous plan to develop the 12-ton CG-2000-3 engine, there were plans to introduce the D-18T engine's large-diameter fan blades made by the Motor Cic company.

So at first glance, it seems that United Aero Engine has made a breakthrough in large-diameter fan manufacturing technology, but after really learning about the fan blades manufactured by the Motor Siqi Company, Yang Hui can be regarded as wanting to scold his mother, the D-18T engine manufactured by the Motor Siqi is actually the same technology as the early JT-8D engine fan of Pratt & Whitney, that is, it is the same as the current CG-2000 fan blades, which are made of solid titanium alloy blades.

The difference is that these two guys make the root of the engine blade strong enough, although this will bring the effect of discounting the fan intake efficiency, but it does make the fan diameter of the D-18, JT-8D, CF-6 and other three engines large enough.

However, if United Aero Engines were to be asked to follow the technology of the 60s in the future to produce large-diameter fans of more than two meters, I am afraid that this kind of engine would not be very attractive even if the army of the Republic was notoriously not picky.

At present, in front of United Aero Engine, this time only the French composite blades or the British honeycomb hollow titanium alloy blades can be used, as for the two giants of the United States

It's really embarrassing, these two giants really can't live up to their names in this regard. Pratt & Whitney is following Rolls-Royce and planning to take the road of hollow titanium alloy blades, but Pratt & Whitney is still a generation behind Rolls-Royce, so there is nothing to show off.

However, GM was lucky, through the CF-56 engine project, and had a good relationship with the French side, and finally got the composite fan blade technology authorized by the French Snecma company, and then used this technology to manufacture the world's largest super-large duct ratio turbofan engine GE-90, the size of the entire fan directly exceeded 3 meters, and the engine was thicker than the Boeing 737 body diameter after the whole engine was assembled.

The composite material is indeed light enough, and even the composite blades are better than Rolls-Royce's honeycomb titanium alloy blades, so this time Mr. Wen is quite smart, and he has taken a fancy to the more promising composite fan blades, and this can also effectively share the development costs of composite materials, so no matter what aspect you look at, this is a very good choice.

Several other older generations who participated in the meeting did not know what the benefits of composite fans were, but those engaged in aerospace must know how useful composite materials are, as long as they involve composite materials, then they must vote, I believe that when composite materials can be used in aero engines, it makes no sense that there can be no suitable composite material technology on the aircraft body, as long as the composite materials continue to be developed, these are the science and technology trees that can be lit.

In this way, the research work on composite materials was almost unanimously approved, and in the end, Yang Hui set the tone for the project.

"Whether it is the use of resin matrix composites to manufacture aero engine fan blades, stator blades, casings, containment rings, fan front caps, or even the ceramic matrix composite tail nozzle that has just been proposed in the world, or the body parts made of resin matrix composites, these are the application scope of composite materials, so I call these projects collectively called "the manufacture and application of advanced composite materials", and this project can be included in the 924 aviation revitalization plan. ”

Sure enough, to be a leader is to learn to summarize and summarize a high degree, and to be able to flexibly use some lofty words, at least this "manufacturing and application of advanced composite materials" is a project that sounds lofty, and it feels really exciting.

As long as the project can be included in the 924 plan, although the entire 924 plan is only about one or two hundred million yuan per year, the amount allocated to the composite materials is probably only tens of millions.

But these tens of millions are definitely a lot, after all, this is a fixed investment of so much money every year, I think that when the time comes, the R & D unit will find a way to make up some more, and then the United Aero Engine Company will give some funds, and it is enough to carry out the research of the project.

Thinking of this, Mr. Wen felt that it was necessary to give everyone a good news first, stimulate everyone in advance, and let everyone be full of confidence in the cause of composite materials.

"By the way, although we learned from the motor that they make solid titanium fan blades that are similar to the technology we used for the CG-2000, we have also learned that the 56 stator rectifier blades behind the low-voltage fan of the D-18T engine are made of carbon fiber reinforced resin-based materials, and we have purchased this technology and are preparing to continue to develop our own composite fan blades based on it." (To be continued.) )