Since it is a turbofan engine, it is natural to spend a lot of effort on the design of the fan, excellent turbofan design can make the surge margin of the engine go to a higher level again, and it can also enhance the ability to resist foreign strikes and reduce the weight of the fan, these advantages are quite important in the design of military turbofan engines.

Titanium alloy as a blade material is naturally a must, without this thing to go out you are embarrassed to say that you are the third generation of the engine used by the turbofan, especially in the field of thrust engine, fortunately, the current Southwest Science and Industry can carry out more complex forming processing of titanium alloy, and there is no problem in this regard.

As for the use of turbomachinery ternary flow theory design in the fan design, this is even more worry-free, Southwest Science and Industry has the founder of this classic theory, Wu Zhonghua, the old man, as early as after the core machine was finalized, this was invited to the Southwest Science and Industry to guide the design, which is naturally not to worry.

As for the problem of the final wide-chord fan blades, there is no place to be lazy, although the fan of the CG-2000 engine also uses this kind of thing, but due to the huge difference between the two engines in the bypass ratio, it is destined that the fan design of the two engines is difficult to have much in common.

However, at this time, Southwest Science and Industry can still have a more direct way, directly contact with MTU, and seek technical support from MTU.

"The reason why we dare to use the wide-chord fan design in Xinzhong this time is that we in Southwest Science and Industry can cooperate with MTU and get help from MTU in the design of the fan. Taking 10,000 steps back, even without the technical support of MTU, with the technical research ability of our Southwest Science and Industry, we can also come up with usable technology within the specified time. ”

Chief Master Li kept explaining on the stage. For the most difficult wide-chord design in the fan design, he also focused on explaining, and some participants who paid more attention to the southwest science and industry naturally understood what he just said.

But there are always people who don't know where the confidence of Southwest Science and Industry comes from, such a tall design of wide chord fan blades is still being developed by the current international three giants or has not been put into use for a long time, Southwest Science and Industry actually thinks that the small MTU has this ability. It's simply ......

"Don't think about it, with the little technical ability of the MTU company, how can the aero engine subsystem developer, which does not even have a finished turbofan engine, master such a technology, and you should not think that the Germans are omnipotent."

After these words are spoken, as long as everyone can feel the strong sense of superiority in this person's heart, I don't know where his superiority comes from? Is it because the aviation industry of the republic has a complete range of types, but it understands everything and everything is average? If that gives him confidence, then

These words came from the lips of the leaders of the Ministry of Aviation Industry in the front row. The people who knew some of the truth in the back row were also stunned, and even the opponent of Southwest Science and Industry this time, General Engineer Meng of Hongqi Factory, was also surprised by the behavior of the leader of the Ministry of Aviation Industry.

Hongqi Factory also participated in the bidding of the MPC-75 power system, and still knew the technical ability of the opponent......

After thinking about it, Director Meng still feels that it happened yesterday, and it is obvious that Rolls-Royce also has a positive attitude towards MTU's wide-chord fan blade technology. As for whether MTU's wide-string fan technology has anything to do with Rolls-Royce, it's unclear.

I was about to remind this leader who was very optimistic about the Hongqi Factory, but Chief Li on the stage acted faster. At this time, the Southwest Science and Industry was not afraid of offending the Ministry of Aviation Industry, and the relationship between the two sides had always been bad anyway.

"What the leader said is not right, we Southwest Science and Industry to seek MTU technical assistance is naturally our considerations, we cooperate with MTU to develop the CG-2000 engine has been assembled and tested, for MTU in the wide chord fan technology attainments are still relatively clear. By the way, the fan of the CG-2000 engine is also designed with wide-chord fan blades. The diameter of this fan is up to 1462 mm. ”

This naked slap in the face also made the leader of the Ministry of Aviation Industry say nothing more with a black face, he also secretly looked at the expressions of other people just now, and even the person behind him secretly kicked his ass, how obvious this situation is.

Eyes on the ceiling. With his nostrils facing the sky, he said in a strange manner: "I think about relying on foreign technical support for a day, relying on mountains and mountains, relying on water and water, and the Germans are also unreliable, anyway, I am not optimistic about your approach to seeking technical support from MTU, I reserve my opinion." ”

Hearing this, Yang Hui smiled, at this kind of meeting, you said that you are not optimistic about the plan, then there is no problem, but what does it mean that you have a reservation later, and you don't need to reserve your opinion here, if you have an opinion, you can put it forward, anyway, I Southwest Science and Technology Industry will not change.

After this small episode, the meeting continued.

Since the design of the fan lists such a tall and tall technology, Mr. Li naturally wants to have a horizontal comparison, only the horizontal to the international level of the same level of engine technology, naturally can show the new turbofan engine fan design excellence.

"There is no need to elaborate on the use of titanium alloy in the manufacture of fan blades of medium-thrust military turbofan engines, whether it is RB-199, F-404, or even military high-thrust turbofan engines, titanium alloy is used as the fan blade material."

Then a slide was replaced, which was replaced by information on the design of the wide-chord fan blades used in military turbofan engines.

"The use of wide-chord fan blades on military turbofan engines is also the first time in the design of the F-404 engine, although the F-404 at that time was still somewhat conservative in the use of wide-chord fan blades, and still retained the design of the shock-absorbing boss, but the later use shows that the military medium-thrust turbofan engine can fully use the wide-chord fan design, and the Swedish RM-12 engine is a typical example of this design."

When Mr. Li brought the topic to the Nordic countries: Sweden, at this time, few people could figure out what Mr. Li said, about the Swedish RM-12 engine, that thing is the engine of the JAS-39 fighter, derived from the American F-404 design basis, through small local changes to increase the thrust of the F-404 to the level of eight tons, and these small improvement schemes, there are improvements to the F-404 fan design comprehensive wide chord design

"We can eliminate the crown design of the fan with the same wide-chord fan design, which can not only greatly optimize the efficiency of the blades, but also reduce the weight of the entire fan and reduce the processing difficulty of the blades.

Speaking of which, Chief Engineer Li has to come up with another major technical advantage of the new Zhongtui behind the fan, which can be regarded as a surprising "side effect" after the adoption of the wide-chord fan design.

"Since our mid-push core machine already has a 12 percent surge margin, with a wide-chord fan blade design, the surge margin can rise to about 28 percent, which fluctuates up and down by up to one percentage point. In view of this situation, we are ready to eliminate the variable curvature inlet guide vanes of the engine in the design of the new mid-push push. ”

As soon as these words came out, they shocked the four again. To cancel the engine import guide vane, this design is definitely quite a risky program, in this plane military turbofan engine really dare to cancel the imported guide vane design is only RB-199, people dare to do this because of people's excellent technology, the use of three-rotor design to bring about the ultra-high surge margin is all the twin-rotor engines at that time can not achieve the index.

Now the 28% surge margin given by Southwest Science and Industry can be compared with the surge margin of RB-199, but to say that the import guide vane is canceled on the twin-rotor engine, everyone is still a little unacceptable psychologically. (To be continued.) )