A Man of Science and Engineering in Troubled Times Wandering in the Late Qing Dynasty

Chapter 358 The Newborn Calf
Li Yu quickly got the new Kodak pocket camera sent by Eastman, and it was a bit cumbersome to use.

Moreover, it is troublesome to go to a special photo studio to develop photos.

Konoe Zhaoxue was very clever. When she saw Li Yu playing with the pocket camera, she quickly learned it. She came over and said, "Sir, I have learned how to develop photos. In the future, I can handle this matter."

She now wants to get intelligence information in every possible way. Like telegrams, photos are also a very effective way.

Li Yu also plans to install darkrooms in his laboratory on Fifth Avenue and in his domestic mansion in the future, which will be much more convenient.At present, it seems that she is the only one who can do it, so she can only agree temporarily: "Be careful in the process."

Li Yu, one of Konoe Zhaoxue, pointed out that the negatives, developer, fixer and other materials needed to develop photos are more expensive, so he said: "Don't worry, sir, I am very quick."

As a spy, developing photos is of course one of the must-have skills.

Although Li Yu knows the general process, developing photos is really time-consuming. The negatives must first be developed→fixed→washed and dried, and then the negatives can be used to enlarge and print the photos. Developing→fixing→washed and dried is required again. .

Anyway, it definitely requires a certain amount of technology and proficiency.

In the late Qing Dynasty and the Republic of China, taking pictures was expensive, and to a large extent it was expensive to wash.

However, modern people like Li Yu cannot do without taking pictures.It is said that in my previous life, after a good meal, I had to let the camera eat before I moved my chopsticks. This problem is hard to change.

A day later, the Bells found Li Yu and were about to leave for North Carolina.

Li Yu first sent a telegram to North Carolina, and the Wright brothers wrote back saying that they would meet at Duke University first.

In fact, Duke University should be called Trinity College now, but it is easy to confuse it with Trinity College in Cambridge. For convenience, it will be called Duke University directly in the future.

There is no big problem, because Duke University changed its name because of the donation from the tobacco tycoon Duke, and Duke had already donated a lot of money as early as ten years ago.

On the way, Li Yu gave Bell an overview of the situation of the Wright Brothers. Bell said, "They sound like two very thoughtful people who asked us to meet at Duke University. Could it be that they encountered technical difficulties?"

Li Yu said: "Perhaps. After all, I have seen their first flight test. If you want to improve it, the difficulty will be greatly increased. It is only natural to seek help from the university."

Bell said: "That's it, that's why my Aeronautical Experiment Association needs to recruit more powerful talents, just like you, Academician Li Yu."

Li Yu said with a smile, "Mr. Bell is over the top."

Most of the famous universities in the United States are concentrated in the north, and Duke University should be the best university in the south of the United States.

Song Jiashu, the father of the three Song sisters, graduated from Duke University, as well as Tim Cook, the boss of Apple.

The school is famous for sports, especially basketball.Don't underestimate that the famous "Ivy League" is actually a college sports league.

Anyway, Lao Mei attaches great importance to this aspect.

At the beginning, I didn't understand why the famous schools in the United States paid so much attention to students with specialties in a certain field, including sports. Later, I realized that this is also a selection mechanism.

A person who can study well and also have a specialty can at least explain two problems: one is that the student himself is excellent;

Orwell Wright, the younger brother of the Wright brothers, came to greet him specially, "Academician Li Yu, I am so glad to meet you! We have carried out key research on the balance control of the aircraft in the air as well as take-off and landing according to your last request. , but the two of us found that many engineering problems were involved, so we had no choice but to turn to the university for help."

Li Yu said: "It's a very legitimate reason. When everyone gathers firewood, the flame goes high."

Li Yu introduced Bell to him again. Now that Bell is a big celebrity, Orwell Wright certainly knows him: "It's an honor to meet you! We often use the telephone invented by Mr. Bell."

Bell said: "You guys admire my phone, and I want to see your plane. In Mr. Li Yu's Chinese language, it's called Reciprocity."

"What you said is correct," said Orwell Wright. "Please, please, we have invited some students and lecturers from the Faculty of Science to do theoretical research together."

Bell's heart tightened when he heard this: Their movements are so swift, maybe they will really make a world-famous aircraft before him.

Duke University, a university in the south of the United States, has many campuses that are very large.In addition to the donor tobacco tycoon Duke, another philanthropist Julian Carr donated a lot of land, so Duke University has no shortage of buildings.

The big guy entered a classroom temporarily used by the Wright brothers, where a few students were immersed in calculations, and the older brother, Wilbur Wright, was discussing engineering improvements with a lecturer.

After saying hello, Li Yu looked at the calculations that the students were doing, and he froze instantly. He went over to the students and asked, "Which department do you come from?"

The student replied: "Dear Academician Li Yu, we are from the Department of Mathematics, Faculty of Science."

Li Yu took a closer look at their play paper and asked, "Is this the Navier-Stokes equation (NS equation)?"

The student said, "Yes, sir."

Li Yu gasped, good guy!To do such a difficult thing!
But the research direction is right.

Because the NS equation belongs to fluid mechanics, aerodynamics is of course a fluid field, so the research of aircraft cannot get rid of many fluid equations.

The NS equation is one of the big keys, and it is a set of extremely difficult partial differential equations.

Partial differential equations are also required for physics majors. In fact, engineering majors must also learn this course.

As mentioned before, partial differential equations are very, very, very, very difficult, so difficult that they explode.

So there is no need to know too much specific knowledge, and it is impossible to know much specific knowledge... It is enough to know the difficulty, importance, and applicability of general science popularization.

Really "magic" is not an exaggerated word.

Even the simplest partial differential equation, such as a one-dimensional heat conduction equation.The meaning of physical interpretation is: there is a rod, the initial temperature is a specific value everywhere, and then a heat source comes from the right to solve the temperature at a certain point.

The form is very simple, there is only one line, and there is only one variable. Does it sound like a simple junior high school problem?

Hey!

If you see the analysis and solution process, you will find that even if you copy the answer for you, you will not be able to understand it.

It's a bible at all!

This is only one-dimensional and has only one variable. In real life, it is three-dimensional. If you need to add the Laplacian operator, how can you describe the difficulty...

Just like the teacher was still talking about 1+1=2 last second, he lowered his head to pick up a pen, then looked up again, and he had already talked about advanced mathematics in college.The difficulty span is even wider than that.

Although Li Yu is not from the Department of Mathematics, partial differential equations are one of the mathematical tools that physics majors must learn, so I still have some contact with them.

He felt his scalp go numb looking at the things in front of him.

Bell glanced at it, as if he saw a Chinese or Japanese language he had never seen before, and asked in surprise: "Do you need this for flying?"

Naturally, the students also respected Bell, so they replied sternly: "Yes, Mr. Bell! Mr. Wright gave us a subject, which we didn't pay much attention to at first, but later found it very challenging, so we spontaneously organized to help."

Bell said: "I heard that your school is theology-based, but there are really people who understand such complicated mathematical knowledge."

The student laughed and said, "Mr. Bell, there are people who love science in the South. I think God must also be obsessed with solving this most beautiful equation!"

Students should be religious, which is normal at Duke University, which is still called Trinity College.

Bell is a graduate of University College London.

When UCL was founded, both Cambridge University and Oxford University in the United Kingdom were church universities, so UCL intended to become a secular university choice other than religious ones.

Therefore, graduates of University College London are relatively more advocating science.

That's why Bell always looked down on Duke a bit at first.

Bell asked Li Yu again: "Are you sure you need this thing to develop an airplane?"

Li Yu spread his hands: "To be honest, of course it is necessary. However, the Navier-Stokes equation obviously will not be solved in another 100 years, so it is not so indispensable."

What Li Yu said was the truth. After all, before he crossed over, the NS equation was still far away from being solved.

Wei Dongyi and Wei Shen are studying the NS equation, which has been popular on the Internet, but even if it is so popular, you can see how many people have explained the specifics. This stuff really doesn’t seem to be studied by humans. Not many people.

As one of the seven millennium mathematics problems, if the NS equation can make substantial progress, human beings can really explain why the plane can fly.

Many people should have this question: Since the Navier-Stokes equation cannot be solved, how can the plane fly safely and smoothly?
For example, how do you know how much lift the aircraft receives when flying at a certain speed and at a certain angle?What is the resistance?

It is based on the empirical formula!

It is also necessary to explain in a little detail what is called the empirical formula.

College engineering students should have seen many empirical formulas. Since it is called "empirical formula", it means that it cannot be explained by mathematical principles. ——Because it is not deduced at all!

This is also one of the reasons for the slow and limited development of traditional disciplines in Li Yu's last life.

The empirical formula has many coefficients. To obtain these coefficients, the aircraft must be placed in a super large wind tunnel, and then some fluids visible to the naked eye will flow through it, and the values ​​of the coefficients can be obtained through experiments.

Then you need to measure many different graphs: for example, the graphs of various coefficients of the aircraft under different aspect ratios or different pitch angles, etc.

Specifically, there are many troubles.

However, although the empirical formula is very useful in many engineering fields, it has a big problem: it is specific, such as a certain form of wing shape, and cannot be changed at all.

If you want to design a new shape of the wing, you have to start all over again. The above empirical formulas are all useless, and you need to put it into the wind tunnel again for testing.

Because the initial conditions have changed, the result is completely different. After all, the differential equation contains chaos.

However, once the Navier-Stokes equations are worked out, there is no need for a wind tunnel!
As long as you have the shape of the wing, it is equivalent to having the initial conditions, and you can even calculate all the flight data by hand, and there is no need to do experiments.Of course the computer is faster.

How can this save tens of billions!

So Li Yu has always felt that if Wei Shen can solve the NS equation, let alone the 100 million dollar bonus for the millennium problem, even if he is given [-] million dollars, it will be a small amount.

Just kidding: by solving this equation, humans can design circular flying machines!
Because it is possible to design the best wing shape in a certain fluid state.At that time, UFOs may really come true.

In short, this is why Li Yu dared to give the airship information to Little Japan.

——The NS equation can't be solved!

No matter how much money Japan invests, it will not be of much help to future aircraft development. It is time-consuming and laborious, and it is thankless.

I don't know if this is a conspiracy or a conspiracy?
Li Yu knows Little Japan very well. They are ghosts and ghosts. It is difficult to handle them without some high intelligence.

It has to be useful for the moment, it has to be very difficult, and it has no prospects!I can't really help Little Japan.

Such things are really hard to find.

As for the student at Duke University in front of him, it is a different situation: just like when Chen Jingrun researched the "1+2" ​​Chen's theorem, many minkes flocked to study Goldbach's conjecture.

This student obviously didn't know the horror of the NS equation.

To put it bluntly, his mathematical foundation is not in place at all, so he made such a rash attempt.

Li Yu kindly reminded: "Engineering can sometimes use some simpler methods."

The student said: "I understand what Mr. Academician means, but if you solve the equation, it will be more convenient and save a lot of money."

Li Yu said with a smile: "The research of engineering technology is like selling gold, which is normal."

The student seemed determined: "I think God must know everything, and the secret of the plane is hidden in the Navier-Stokes equations!"

People with faith are really persistent, and Li Yu can't persuade them at all.

Brother Wilbur Wright said to Li Yu: "Sir said last time that we can provide another engine. Can we put forward some requirements for it, mainly a few important parameters, such as weight and power."

This was what Li Yu had promised, so he said, "Of course, Mr. David Buick has been researching the engine, and I will give you an engine that satisfies you."

After seeing the designs on paper, Bell wanted to see the real machine even more, so he said impatiently, "Let's go to the hangar as soon as possible!"

The Wright Brothers respected Li Yu and Bell very much. Since Bell said so, they could only stop the data research at hand and take them to see the last Aviator 1.

It has to be said that compared with the designs of others such as Bell, the aircraft designed by the Wright brothers is really too advanced in shape.

Bell again had the Wright brothers tow the plane out for another flight test.

Same as last time, the plane flew two 300 meters.

Rao is so, it has already made Bell amazed.

"It turns out that it is really possible!"

In addition to Aviator 1, there is another Aviator 2 under development in the hangar.

It's just that the Wright brothers' patent has not yet been approved, so they can't show Bell more technical information.

However, Bell finally made a clear research direction.

Bell asked Li Yu privately: "Sooner or later, this patent will belong to the Wright Brothers. Can we continue to study it?"

Li Yu said: "Just like a car, there are still many aspects that can be improved in an airplane, and there is still a lot to do, especially if we can make a better layout design."

Bell didn't know much about aerodynamic layouts, but when Li Yu said this, he generally had a clue in his mind.

"You must join my Aeronautical Experiment Association!" Bell told Li Yu and the three of us.

He was afraid that Li Yu would run away.

Li Yu said with a smile: "I know, I still have to pay for the founder of the technology."

Bell was very satisfied: "It seems that I will be able to take a powered aircraft to the sky once in my lifetime!"

Not only him, Li Yu is also looking forward to it.

In addition to running on the ground, Li Yu also engaged in flying and swimming in the sea.

Not just for fun, they will be of great use in the future.

(End of this chapter)