Go back to the past and be a schoolboy

Chapter 173
"Papaya, why are you here so early today? I usually have theoretical classes in aviation school, but I've never seen you be so active. What's the matter, the sun is coming out from the west?"

Just as he put down the book in his hand, before he could pull out the stool, Chen Tiancai turned his head and caught a glimpse of his best friend already preparing homework on the seat, his jaw almost dropped from shock.

Time flies, and the end of 1917 came in a flash, and the careers of the varsity team and the aviation school were gradually on the right track.

In addition to some necessary physical fitness classes, the students of the aviation school and the members of the varsity team have been selected, and the usual training is gradually separated.

However, while training pilots and escorts, Cheng Nuo deliberately used his connections and reputation from various colleges and universities in Beijing and Tianjin to find a group of relatively good seedlings to train flight designers.

Considering that although some members of the varsity team failed to be selected as flight designers, they still had great interest in aircraft. After consulting their opinions, a group of them were recruited and transformed into ground staff, and some of these people also took mechanical courses.

Chen Tiancai and Xia Sigui, who were in the same batch, were hired as ground staff.

"Look at what nonsense you are talking about. Today is the dean's class in person. Who dares not come early? I think he is tired of work. If you come late, you have to sit in the first row. I know what this means. The chief will personally test you." Xia Sigui just glanced at his friend, then quickly turned his eyes back to the book.

"Hiss, you almost forgot if you didn't tell me. Just to be on the safe side, I'd better take a second look. Last time, I passed the assessment of the material class. I can't hang around like this again this time." The more Chen Tiancai thought about it, the more afraid he became. He sat down on the chair and began to read a book.

In fact, it’s no wonder they are so cowardly. Firstly, they were born at the bottom of the class, and it’s already a great thing to be able to write their own names in their hometown. Now, they directly cross several thresholds and learn this kind of knowledge purely by rote. The use of things has to be delayed.

Secondly, the "Aircraft Materials" course taught by Cheng Nuo is considered a cutting-edge subject in today's world, and it is difficult for an insider to learn it, let alone the two of them are laymen.

Ever since, during the period before the class bell rang, the classroom was surprisingly quiet, especially the students who came late and sat in the front row. Some people were so nervous that they kept sweating and wiped their hands over and over again. Can't finish it.

"Zhang San, please take it easy, lend me the notes from last time, so that I can draw the key points, and don't wait for the dean to ask me questions."

"Why don't you read Li Si's notes, he was the one who remembered quickly and completely last time, I didn't remember so much at all."

"That guy's handwriting is like a shrimp dancing. The old Wangtou in the village learned the ghost charms from him. Who can recognize him. Last time I pointed to a sentence he wrote and asked him for a long time, he looked at it for a long time , In the end, he told me that he didn't know what he was writing, so tell me this..."

"Wang Er, you call people's tongues behind your back, that's not authentic, don't borrow my things next time, and save me from getting in your way!"

Seeing that a few people were about to quarrel, a handsome young man in a long robe suddenly came from outside the classroom, with a thick stack of copywriting in his hand.

Seeing this person coming in, the classroom immediately fell silent. Except for a few who looked at him boldly, the rest of the students buried their heads in their textbooks, for fear of meeting their eyes.

"stand up!"

"Good morning, teacher!"

"Please sit down, students, good morning!"

As the class bell rang, Cheng Nuo stood in front of the desk and waved to everyone with an inexplicable smile on his face: "Students, I told you in the first class that as a student, you not only have to learn The knowledge in the textbook should always pay attention to the changes around you.

A big event happened around us recently, is there anyone willing to answer. "

Perhaps because of Cheng Nuo's prestige, none of the students below were willing to stand up and answer the question, even though it seemed so simple.

Cheng Nuo had expected this for a long time, and stretched out his index finger and said, "Those who answer the question will get 10 extra points!"

After listening, some students couldn't bear the temptation of the usual share, and hurriedly raised their hands.

I don’t know if I don’t know it, let’s put it aside, and I’ll think about it after I stand up. The main reason is that the usual 10 minutes is really delicious.

Because Cheng Nuo said in the first class that the final grade = ordinary score + midterm grade + final grade, and adjust according to the corresponding ratio, so the quality of the usual score is related to the level of undergraduate grades.

"Sir, I have an idea." After getting permission, a tall and thin man stood up and replied.

"Oh, tell me, don't be nervous, because you are the first person who is willing to answer this question, regardless of whether the result is right or wrong, this point will be added to you, of course, there is no right or wrong in objective facts, You can say it boldly." Cheng Nuo came down from the podium, stood beside the man and encouraged him.

"That's right. I like to read newspapers. Recently, "Shenbao", "Times", and "Morning Bell" began to report on the Red Revolution of our northern neighbor Mao Zedong. Although the evaluation opinions are different, they are not bad at all in my opinion. The three people proposed by Mr. Sun..." Talking about this, the student couldn't hide his enthusiasm.

However, there are some things that are not suitable to be said in public. For the sake of the students and everyone else, Cheng Nuo hurriedly stopped the students.

"This matter is not as simple as you imagined. We will talk about it later when we have a chance."

Patting the student on the shoulder to let him sit down, Cheng Nuo thought for a moment, and then walked towards the center of the classroom: "Well, let me limit the scope of application. Regarding this school, it is the same as before. The first person to answer the question, no matter whether it is right or wrong, usually divides it up." All add 10 points."

Although the scope of application has been increased, but with the example of the students in front, the students who raised their hands to answer are more unscrupulous.

Fearing that Cheng Nuo could not see the students in the row behind, Chen Tiancai stood up directly: "I heard from other teachers that our school was founded to help victims of disasters like us. It raised 500 million yen, saying it will be used for post-disaster reconstruction.

Does this meet the requirements of Mr. "

Cheng Nuo sighed silently in his heart. It's not too much to divide the three to seven, but he didn't know what to sell.

But obviously these things are not what Cheng Nuo wants to know, society is already cruel enough, he doesn't want the students to know this for the time being.

Perhaps the timing was not yet ripe, Cheng Nuo thought about it and forgot it, and walked to the podium again.

"Okay, it seems that you are not very clear about what happened in our aviation school for the time being, but it will be soon, and you will see it in a short time. Now let's officially enter the classroom time. First, as usual, I will find a few Students answer the homework assigned after class last time, then start from the first row.

First of all, let me answer why the landing gear part does not use traditional metal? "

"Uh... this... this is because the main landing gear of the aircraft is subjected to the impact force of dozens or even hundreds of tons at the moment of landing, so it is necessary to use ultra-high-strength structural steel with good impact toughness..."

In this way, after a few questions, the students were like lambs waiting to be slaughtered, trembling in place.

Of course, designing an airplane is not a matter of simply throwing out the theory. Even if Cheng Nuo handed over the design drawings, it cannot be completely imitated.

Especially when the aircraft takes off, ascends, runs at high speed, and lands, it will be subjected to a large external force, and the force received by each part of the aircraft is also different, so its mechanical properties must meet the standards.

In the same way, the aircraft is subjected to harsh weather conditions during flight, industrial pollution, salt spray, relative atmospheric temperature, humidity, flight altitude, range, runway conditions, coolant, fuel, hydraulic oil, battery fluid, etc. will all have harmful effects on the aircraft. The atmosphere that a little corrosive material volatilizes, and the corrosion resistance must also be qualified.

However, due to the effect of the earth's gravity and air resistance, it is required that the lighter the aircraft, the better, so the production of the aircraft requires light metal.The lighter the aircraft, the higher the aircraft will fly, farther, faster, and the loading capacity will be larger, and the fuel consumption can be reduced, thereby increasing the economic effect on society and nature.

All kinds of factors add up, even with the foresight plug-in, there is no guarantee that the aircraft can complete the construction of the prototype as soon as possible.

Just when Cheng Nuo finished his class and was about to enter his office to take a break, there was a sudden commotion from outside.

"Listen quickly, is this the sound of a dragon roar?"

"Hiss~ I've never heard this kind of sound before, it really seems like a dragon's voice."

"What are you talking about? Take a good look to see if this is an airplane. It's fine if the students of our varsity team don't know it, and the students of your aviation school don't know it either. Isn't this a joke?"

"I remember that the planes at Nanyuan Airport don't fly like this, and the sound is not as loud."

"Don't even look at it. This plane is much better than those antiques in Nanyuan. The shape is far worse than that. In my opinion, the appearance is one of the experience standards for the combat effectiveness of an aircraft. A good-looking aircraft is just as powerful as it is. Not bad."

……

The students raised their heads one by one and tried their best to look at the plane in the sky. Wherever it flew, their eyes were focused there, and they talked a lot.

It's a pity that no matter what you say, no one wants to believe that it is a domestic aircraft. After the plane landed safely and the pilot came out of the airport safely, they still couldn't believe it.

Even Cheng Nuo was one of the confused ones.

But now that such a big event happened, Cheng Nuo, as the person in charge, of course had to rush to the scene as soon as possible.

When the pilot over there saw Cheng Nuo approaching, he directly saluted: "Dean, fortunately, the F-1 single-wing all-metal prototype has successfully tested its flight!"

Hearing this, Cheng Nuo was immediately a little dazed. He never thought that the other party would come out like this. Like other students, he didn't know the specifics about the flight test for the time being.

Just as he was thinking about how to deal with each other, Bayuzao and Wang Zhu directly squeezed into the crowd and told them all.

It turned out that after receiving Cheng Nuo's improvement suggestion, they went back and worked overtime to demonstrate. The data calculated on paper proved that the performance of the improved aircraft was even better, and the safety was also greatly improved.

At this point, they began to work overtime day and night, and the prototype was built in a few months.

However, because it is a rare monoplane with an all-metal structure, not to mention ordinary pilots, even old test pilots stand alone in front of this F-1 aircraft, and their hearts are terrified.

Even if they look carefully, they can still find that there are still many unpolished rivets on the plane, and the safety of the plane is really not guaranteed.

However, seeing that the plane had landed smoothly, Cheng Nuo's heart sank a lot, but his face was still very serious: "Next time there is such a major project, you must notify me in advance. Mistakes are acceptable, but cheating Not the way of our Academy of Sciences."

Bayuzao promised again and again: "This is not an example!"

But right now was obviously not the time to talk about business, Cheng Nuo went back to the office, took out the blueprints of the plane that the two had improved, and looked at it carefully.

With the foundation of many excellent aircraft in the past, the design of F-1 was quite perfect at that time. The structure, materials, wings, high-lift devices, instruments, engines, etc., all have clear data support, and it looks quite good. .

However, after many days of study, Cheng Nuo still found some problems.

"Are you sure you want to use curved airfoil blocks for this plane?" Cheng Nuo picked up a pencil and circled the wings of the plane and asked.

At the beginning of the invention of airplanes, designers mainly researched and designed wings based on the shape of birds' wings.From Lilienthal, Phillips to the Wright Brothers, the airfoils used are all arched double camber thin airfoils like bird wings.

Especially in terms of the relationship between airfoil and lift and drag, people at that time believed that curved airfoils were beneficial to generate greater lift.

The smile on Bayuzao's face gradually faded: "The specific parameters are obtained from wind tunnel tests, and the current aircraft all adopt thin airfoils with curvature."

Cheng Nuo smiled and shook his head: "That's right. Although the airfoil of this type of aircraft can generate greater lift, it also has a lot of resistance, so the lift and drag of the wings are relatively low."

Wang Zhu seemed to understand: "In other words, there is still room for further improvement of the F-1 prototype?"

Cheng Nuo threw the pencil on the paper and said with a smile, "Of course, the lift-drag characteristics of relatively thick wings are better than those of thin airfoils, with higher lift coefficient and lower drag coefficient... "

Although the design and test flight of the new all-metal aircraft was very successful, especially in the Far East, it was an epoch-making existence. Basically, no aircraft can exceed the performance of the F-1.

However, advanced is only relatively speaking, and it is more of a path-finding work of the Academy of Sciences regardless of cost, and there is a lot of room for improvement.

For example, innovations have been made in endurance time, cruising range, flight altitude, rocket-assisted takeoff, and aerial refueling, and research has been conducted on passenger, cargo, and later military types that have all won orders, thereby achieving huge commercial achievements.

When the time is right, it will be smoothly transferred to the military to prepare for special needs in the future.

So despite the successful test flight of F-1, Cheng Nuo still has high requirements for it.

(End of this chapter)