The military-industrial scientific research system of the academic master.

"By the way, Teacher Du, this is actually why I came to you this time..."

Chang Haonan took out a floppy disk from his bag and handed it to Du Yishan. After looking at it twice, the latter inserted the floppy disk into the computer next to him.

Although Du Yishan is very old, his ability to accept these new things is not bad, and the computer is naturally equipped with various engineering software.

"This is the compressor..."

After adopting a large number of curved and swept designs, the fan blades changed greatly. At first glance, Du Yishan thought that this precious student had designed a compressor blade by himself, but after taking a closer look, he quickly discovered that something was wrong.

Apart from anything else, the size alone doesn't match.

"This is a fan blade that I improved using certain design ideas in the aviation field."

"Fan blades?" Du Yishan glanced at Chang Haonan behind him: "Taking the job from outside?"

"I can't hide anything from you, Teacher Du..." Chang Haonan quickly extended his thumb.

"Okay, okay, stop flattering." Du Yishan waved his hand: "I'm not that kind of old timer. Scientific researchers rely on their own knowledge to earn income. This is allowed by the policy and is also advocated by the school. But you have to pay attention. The first thing is not to delay the main business, and the second thing is not to fall into the enemy’s sugar-coated bullets.”

"Tell me, what do you want me to help you with?"

Chang Haonan quickly expressed his thoughts: "I now want to find a place to actually test the performance changes of the fan before and after improvement, mainly efficiency and noise."

"Well... I can write a note. Our college happens to have a fan duct test bench, which is together with the low-speed airfoil wind tunnel. You can use it." Du Yishan said, pulling out a stack of manuscript paper from the bookshelf and tearing it off. One of them: "But I can only wait until after get off work, and can't delay other people's normal work."

Chang Haonan quickly took the note and thanked Du Yishan.

"By the way, Xiao Chang."

Just when Chang Haonan was about to leave the office, Du Yishan suddenly called him from behind.

"If your improvement is really effective, remember to submit a patent application first and then hand over the plan. There are teachers who have suffered from this before."

……

As a science and engineering university, Beijing Airlines naturally has its own metalworking center. On the one hand, it provides students with metalworking training, and on the other hand, it also processes various things from glassware to metal parts for research groups in need.

There is no 3D printing these days, so it is very troublesome to produce several separate plastic parts.

So in the end we had to adopt a compromise solution, which was to mill out a metal part and then cover it with a layer of plastic.

For the research Chang Haonan is planning to conduct, there is no other impact except that the heavier metal parts may cause greater noise.

After spending 180 yuan and waiting for a day, Chang Haonan got 6 fans that were urgently produced.

1 original design, 1 improved first version design, and 4 second version designs using different bending and sweeping methods.

It has to be said that the craftsmanship of the old masters is indeed excellent, and there is no shoddy workmanship problem that he is most worried about because of urgent needs.

In particular, the mass distribution of several fans is very uniform, which is very important for fans that need to rotate at high speed for a long time.

If the center of gravity is not on the axis of the fan, it is equivalent to eccentric rotation, which will have an impact on life and performance, let alone any accurate data.

It's night, the moon is dark and the wind is high, which is a good time to do experiments.

Since the national standard GB/T 1236 for air ducts for industrial ventilator testing has not yet been promulgated, the current testing equipment is basically diverse.

Fortunately, the basic principles are the same, so Chang Haonan spent about ten minutes to figure out the test operation method, and then used unskilled movements to install the first fan on the speed control motor, and then put the pressure on the U-shaped tube Insert the meter into the static pressure hole. As for the dynamic pressure, it can be read directly with a pitot tube pressure gauge.

There was no way, he really hadn't used such a simple device for some years.

"Click——"

Just as Chang Haonan was clumsily replacing a throttling loading plate with a 20% flow area, the door of the laboratory suddenly opened.

"who!"

"who is it!"

Two voices shouted almost simultaneously.

Especially Chang Haonan, who was concentrating on the experiment, was almost frightened.

"Who are you? Why are you in this laboratory?"

The person who walked in from the outside was a gentle boy who looked a little nervous. After all, the public security was not good these days, and no one could say whether there would be a thief in the school.

And Chang Haonan felt that the other party seemed a bit familiar.

"I am an undergraduate student of our school. I came here to take a test. Academician Du Yishan signed the permission."

Chang Haonan quickly identified himself to avoid misunderstanding.

Sure enough, after hearing his explanation, the other party's mood obviously relaxed a lot: "Academician Du?"

"Uh... yes, my graduation project supervisor for the second half of the year is Academician Du."

While talking, Chang Haonan finally completed the replacement of the throttling loading plate, and then handed the other party the note from Academician Du in his pocket.

"Ah?" Unexpectedly, after seeing Du Yishan's signature, the other party's expression became more confused, and he touched his hair with one hand: "Why didn't I know?"

"you are……"

"You don't have to. My name is Fang Zhen. I am a graduate student in Teacher Du's research group and am in the third year of my PhD." Although Fang Zhen was still a little confused, Du Yishan's signature on the note was definitely authentic, and it seemed unlikely. Some people pretend to be academicians and students just to borrow the laboratory.

But he is the senior brother of the laboratory. Why didn't anyone tell him about the new junior brother?

"My name is Chang Haonan. I just made an agreement with Academician Du two days ago that he... will come to our group to do the graduation project." After Fang Zhen introduced himself, Chang Haonan finally remembered that he had met him in the cafeteria the day before yesterday. He was walking with Yao Mengna and another short girl.

"Teacher Du generally doesn't want to be a graduate undergraduate, so...although I don't know why it was confirmed so early, you should be our future junior brother." Fang Zhen said and walked up to shake hands with Chang Haonan. shake hands.

"I will not officially join the group until the end of this exam week. Academician Du should be preparing to introduce me to everyone then."

Chang Haonan checked the experimental equipment one last time, turned on the power after confirming that there was nothing wrong, and then continued: "The day before yesterday, I saw senior brother you and senior sister Yao Mengna coming at the entrance of the cafeteria. I wanted to say hello, but I didn't catch up."

"Do you know Yao Bo?"

Fang Zhen suddenly felt as if he had become an outsider in the laboratory.

"Yes, I have discussed some academic issues with her." Chang Haonan nodded.

"Well, Yao Bo is very good. He skipped the master's degree and went directly to study for a doctorate. It will really be beneficial for you to communicate more with her."

Fang Zhen's words were not false. After changing the simulation calculation method according to Yao Mengna, although the progress was almost reset, after nearly a month of trying, he was very sure that it was the right direction.

In terms of ability, Fang Zhen's confidence is not much weaker than Yao Mengna's.

But when it comes to enthusiasm for scientific research and the courage to move forward, he knows that he is indeed much worse.