Early the next morning, Du Yishan took the first flight of the day to Hojing, and then met the director Zhou Yonghang and the chief engineer Yi Yuanhe at the 603 Institute.

The former had already called two people last night and asked them to set aside a whole morning.

After meeting, Du Yishan directly took out a floppy disk, which contained the explanatory materials he had sorted out overnight.

Everyone is engaged in technology, and there is no need to talk too much, Zhou Yonghang and Yi Yuanhe quickly realized the value of the things in the floppy disk.

Scientific research, to speak, is nothing more than finding problems and solving them.

But it is often complicated to do it, and it is not easy to find a place to start from the chaotic organization.

Zhou Yonghang and Yi Yuanhe are also well-informed old engineers, but after reading this idea to solve the problem, they still have a sense of unreality.

Generally speaking, the development of engineering models is relatively gradual, and new methods that have just been born are always not mature, and they are often supplemented by old methods or experience when solving practical problems.

The set of things displayed on the screen in front of them was attacked from multiple directions at the same time, and finally converged on the key problem of wing flutter analysis.

In this process, a series of secondary engineering problems, including incremental finite element analysis, aeroservoelastic modeling, and model predictive control, are also solved.

It's as if this method has existed for a long time, and has even been developed and matured for ten or twenty years, but they have never heard of it before.

It's kind of like the feeling when I was first introduced to calculus.

"It has to be Academician Du."

Zhou Yonghang leaned back on the back of the wide seat and said in an admiring tone:

"If I hadn't known that this was a new method you've created, I might have thought ......"

Before he finished speaking, he was interrupted by Du Yishan: "This is not something I created, Du is at this age, and if he wants to make something new in methodology, I'm afraid he can't do it." ”

"That's ......"

Yi Yuanhe next to him showed a curious look on his face.

"It's one of my students, the back waves of the Yangtze River push the front waves."

Du Yishan hesitated, but finally did not say the identity of Chang Haonan's undergraduate.

He was afraid of scaring two old colleagues.

It's not too late to wait until this method is validated.

"Lao Du, if this engineering model is verified, I'm afraid it will ......"

Zhou Yonghang looked at the computer screen in front of him and hesitated, but finally continued:

"I'm afraid it can be regarded as the most outstanding achievement of our Huaxia aviation industry in the field of aircraft design methods."

These words came out of the mouth of the director of the 603 Institute, and they were naturally highly evaluated.

"That's why I'm here for you."

Du Yishan didn't make any twists and turns, put the teacup in his hand on the table in front of him, and went straight to the point:

"Do you dare to validate this engineering model on the Y-7-200A project?"

The two people sitting across from each other glanced at each other.

This is a difficult question to answer.

In terms of the derivation method and the simulation process, they did not find any problems.

But the two and Du Yishan did not think about the problem from the same starting point.

Especially Yi Yuanhe.

This is determined by the different positions of several people.

Starting from the 941 (manned spaceflight) project, Huaxia's engineering projects have gradually determined a main tone:

The chief engineer makes the decision, and the chief engineer is responsible.

Any matters related to the Y-7-200A are ultimately decided by Chief Engineer Yi Yuanhe.

Correspondingly, if the engineering model created by Chang Haonan and recommended by Du Yishan is applied to the design of the aircraft, it is not they who need to bear the direct responsibility, but Yi Yuanhe.

That is, the unity of power and responsibility.

If Du Yishan is put in that position, it must be the same idea.

Yi Yuanhe lit a cigarette, put the filter in his mouth and took a sharp puff.

If this model only involves nonlinear flutter analysis, then there is really nothing to worry about.

Blow a wind tunnel to verify the accuracy of the model, and then conduct a test flight if it passes.

The risk will always be less.

But this flutter is actively suppressed......

It has only been a dozen years since the West first proposed the concept.

It has not even really been applied in the field of aircraft design.

Due to the action problems involving the pneumatic control surface, it is difficult to rely on the blowing tunnel to verify.

Because the scaled wind tunnel model simply does not have an aerodynamic rudder surface, even if it is made, it cannot be manipulated according to the control rate written by Chang Haonan.

As for the full-size model......

The wingspan of the Y-7 aircraft is 29 meters, and it is nearly 35 meters after the new wing.

I can't really find a wind tunnel of this size.

Therefore, it is necessary to test fly directly after the theoretical verification.

That's a big risk.

It is important to know that there is only one demonstrator aircraft currently undergoing airworthiness tests.

In addition to the verification of this project, this Dumiao is actually a verification of the new airworthiness regulation CCAR25 that is in line with international standards.

In case something goes wrong, it is a trivial matter for him to leave a stench for 10,000 years, and it is a big matter to delay the development of the entire Chinese civil aviation industry and aviation industry.

Yi Yuanhe lit a second cigarette.

Du Yishan, who also worked as a chief engineer, knew how much pressure there was in this situation, so he just stared at the flickering cigarette butts through the swirling smoke, and did not rush to urge.

What's more, as he said yesterday in the lab.

Since the 603 Institute is unwilling to carry out this project, it shows that there are expectations and pursuits for this new passenger aircraft.

If Du Yishan's result is as unfeasible as Hawkint's, it will be fine.

But now that this opportunity is in front of them, they can't afford to turn a blind eye.

……

The silence between the three lasted for almost half an hour.

Until Yi Yuanhe finished smoking the sixth, which was also the last cigarette in the cigarette box.

"From my personal point of view, of course, I want to use a more advanced design, otherwise it will be difficult for the new aircraft to open the market. If we just buy a few planes by the head of the domestic airline, it is not the result we want. ”

Maybe it's because he smoked too much cigarettes in a short period of time, Yi Yuanhe's voice is a little hoarse:

"But we still have to talk about science, not brute."

After finishing speaking, Yi Yuanhe put out the cigarette butt in the ashtray, stood up and walked to the window, looking at the runway outside:

"We took two steps, first improving the current No. 01 demonstrator to verify the effect of active flutter suppression, and then replacing it with a new wing for a full-state test flight."

As chief engineer, it was impossible for him to make earth-shaking improvements to an aircraft that was already in a test flight state in the absence of verification just by patting his head.

Being able to make this decision is already under a lot of pressure and risk.

After all, between bold and blind and brutal, many times there is only a thin layer of window paper.

And who can be sure that the score is exactly right?