I really just want to be a scholar

Chapter 610 Isn't it simple?You all understand, right?

Jiang Wei first looked at Ning Qingyun, and Ning Qingyun hurriedly replied respectfully: "Qin Ke has finished watching all of them. I am not so fast. I only read about half of them. They are all the content that Qin Ke picked out to be the most worth watching."

Jiang Weixian glanced at Qin Ke in surprise, remembering that when he first met this kid, he said in the bookstore that he could finish reading a thick textbook in half an hour, and he thought he was bragging in front of girls. The kid can really do it.

It took about a week to read the entire materials in the reference room... You must know that it is all the materials of the research group for more than ten years, and ordinary students may not be able to read them within a year!

This kid is really an admirable genius, no wonder he was able to win the Fields Medal at such a young age.

And Ning Qingjun was able to read half of it within a week, which is quite remarkable. She is indeed the daughter of Ning Zongxun and Ji Xiuyu, and it can almost be said that the blue is better than the blue.

But Jiang Weixian has never been used to praising students easily, he quickly hid the approval in his eyes, nodded and said: "Yes. You have been interns with the class for almost two months before, and after reading the materials in the reference room, you should be able to talk Let's talk about the understanding of the research group of 'Air Turbulence and Climate Prediction'...but the whole research group is too broad, so you can only talk about the difficulties encountered by the current 'Turbulence Group'. Qin Ke, you come first. "

Qin Kelue thought for a while, and replied: "We are a physics team, and we focus on the physical phenomena and laws of turbulent flow. It cannot be said that it is not correct. In fact, the 'turbulent flow group' has indeed achieved good scientific research results in recent years. .but……"

Turbulent flow is disordered or chaotic complex fluid motion, which is also an important reason why no one can solve the NS equation describing fluid flow after 200 years. It is difficult to call it "a major breakthrough". In the final analysis, it is too difficult to deal with at the mathematical level.

According to the data files of the research group reviewed by Qin Ke and Ning Qingyun, after the establishment of the "Turbulence Group", it first started from Bernoulli's law, which was adopted by hydraulics before the continuum theoretical equation of fluid mechanics was established. The basic principle, its essence is the conservation of mechanical energy of the fluid.That is: kinetic energy + gravitational potential energy + pressure potential energy = constant.

However, because it is only applicable to ideal fluids with negligible viscosity and incompressibility, it does not play much role in the in-depth study of turbulent flow, and was soon abandoned. The "turbulent flow group" changed to study Reynolds equation and Lorentz equation group and chaos theory, and came to a conclusion: the specific turbulence is unpredictable, but in the statistical sense, the turbulence is predictable.

The group's attention then turned to Batchelor's law, a law that predicts the dynamics of eddies at different scales in turbulent flows—a law that should really be called a "guess" because it's only derived from physics. confirmed, but no one has ever been able to prove it mathematically.

Two years later, the "Turbulence Group" found that without a deep enough understanding of the NS equations, it would be impractical to study the turbulent phenomena of viscous fluids satisfying the NS equations, so the "Turbulence Group" finally focused on turbulence. The central problem is to find the statistical solution of the basic equation of turbulence, the Navier-Stokes equation.

However, this is a difficult problem that countless mathematicians all over the world cannot solve. It is really difficult for an elite group of physics research groups to solve it.

So after three years of tossing and no outstanding results, the "Turbulence Group" turned back to studying the physical phenomena of turbulent flow, using various testing instruments and data processing systems to measure the characteristic parameters of turbulent flow or display the flow field, and to study how to use various turbulent flow characteristics. This rule improved the existing technology, and finally achieved good results this time. It has made great contributions to the research of domestic large aircraft and engines, and has also given a lot of impetus to weather forecasting.

It can be said that the "Turbulence Group" has gone through the path from physics to mathematics, and then back to physics. This is also the detour that most teams studying turbulence in the world have gone through.

While sorting out his thoughts, Qin Ke continued: "But the problem of turbulent flow is, in the final analysis, a mathematical problem. Unless the problem of the existence of smooth solutions in three-dimensional space for the NS equations of momentum conservation of viscous incompressible fluids is solved, it will never be possible to solve the problem in turbulent flow. A breakthrough has been made in research. The theoretical height determines the depth of application, and the NS equation determines the future application prospects of turbulent flow. I suggest that the 'turbulent flow group' should put at least half of its energy back on the NS equation."

Jiang Weixian suddenly had a smile in his eyes: "This is why you and Xiao Ning decided to study this millennium math problem?"

"Yes."

"Xiao Ning, what's your opinion?"

Ning Qingjun said seriously: "I also share the same opinion as Qin Ke. Now the 'turbulent flow group' can devote half of its energy to studying the NS equation itself, and the other half of its energy to return to the physical level. Only in this way can new breakthroughs be made. Physics Mathematics is inseparable, if the physical phenomenon cannot be described, explained or even proved in the language of mathematics, it is difficult for the physical phenomenon to become a theorem, even if the experiment can be repeated a hundred times, the conclusion cannot be 100% guaranteed to be correct.”

"Not bad." Jiang Weixian finally couldn't help but praise: "You are all right. But to be honest, NS equations are very difficult. I have mainly studied physics in my life. I have asked Lao Qiu for advice on the NS equation, but I still find it difficult." Jiang Weixian has always been pragmatic and does not shy away from exposing his shortcomings in front of students:
"Currently the NS equation can only obtain its exact solution for some very simple special case flow problems, or obtain an approximate solution by simplifying the equation under some preconditions. Our 'turbulent flow group' has only recently It is definitely impractical to further solve the existence of smooth solutions of NS equations in three-dimensional space by conducting physical research based on the known solutions of more than 100 special cases. So..."

The old academician stared at the two proud disciples: "You two are also important members of the 'Turbulence Group'. From today onwards, you will finish your internship and become an assistant researcher. The formal mathematics of the NS equation will be in charge of both of you. In the morning, I devoted myself to researching NS equations in the office, and in the afternoon, I did experimental research with the 'turbulent flow group', and the 'turbulent flow group' continued to conduct research on the original physics for the time being."

After making the arrangements, the old academician provided support: "Of course, if you have any new breakthroughs in mathematics that need to be verified by the 'turbulence group' through experiments, or simulated by supercomputers, you can ask me Bring it up here. I will handle all the resources. Of course, if you need any help in mathematics, you can talk to Wei Yuanfu from the mathematics department yourself."

Apparently, Jiang Weixian also knew that Wei Yuanfu's attention to Qin Kening Qingyun was almost responsive, which was more useful than Jiang Weixian saying it himself.

Qin Ke and Ning Qingyun had no objection to the teacher's arrangement, and were even a little grateful for the teacher's thoughtful arrangement.

After leaving the academician's office, postdoctoral fellow Deng Zhaoliang greeted him and said with a smile, "Oh, I haven't seen you for two months, and I haven't congratulated you in person for winning the Fields Medal."

Deng Zhaoliang just came back today, and he hasn't seen Qin Ke and the others for the past two days.

Since Qin and Ke received the Fields Medal, although everyone in the research team still followed Jiang Weixian's request and treated the two as ordinary graduate students, even if they were senior researchers at the researcher level, they did not dare to arrange for them easily. Work, let alone throwing a face, that's the Fields Medal!The status in the mathematics world is equivalent to the Nobel Prize!
Who dares to treat these two youngest Filipino award winners in history as ordinary graduate students?Therefore, most people greeted them with smiles, showing politeness and respect in their closeness, especially graduate students, doctoral students and postdoctoral students, their attitudes towards Qin and Ke showed a kind of flattering meaning.

This is also one of the reasons why Academician Jiang Weixian adjusted the identities of the two of them from trainee to assistant researcher.

From this day on, Qin and Ke became full members of the "Turbulence Group" as assistant researchers.Don't underestimate this change in identity. In the past, I was an intern with a class, and I didn't even have a say. The experiment was mainly doing chores. But after becoming an assistant researcher, it is basically no different from an ordinary member. You can also propose experimental plans and conduct them independently experiment.

And Jiang Weixian also called the two people to speak by name in every communication meeting, increasing their right to speak in the laboratory.

Time passed very quickly in a hurry, and in a blink of an eye, it was December [-]th, which was Monday. Jiang Weixian was on a business trip, and the deputy director, Academician Guo Weiyang, was replaced to preside over the weekly meeting of the "Turbulence Group".

Qin Ke yawned quietly. Recently, he was obsessed with the analysis and modeling of last year's extreme weather data. He often didn't go to bed until after three o'clock in the morning, and woke up normally every morning. Da Da regained his energy, but the lack of sleep still made him a little drowsy.

Qin Ke was thinking that he would not be able to stay up late like this in the future, when Academician Guo Weiyang suddenly said: "Our 'Turbulence Team' is currently working on the task of 'improving the aerodynamic characteristics of near-space vehicles in hypersonic thin air', Qin Ke, how about Talk about any good suggestions."

The most common use of hydrodynamics is to improve the aircraft. At hypersonic speed, the thin gas flow in the stratosphere will affect the aerodynamic characteristics of the aircraft. How to further improve the shape of the aircraft so that it can fly faster and more stably in the above state , which is the new task that the current turbulence team has received in the last week.

This task is not small, but Qin Ke holds the S-level knowledge "Exploration and Detailed Explanation of the Nonlinear Partial Differential Equation 'Navier-Stokes Equation'", which contains chapters on improving aircraft using NS equations.

Thinking that he has been in the research group for nearly three months and has not made any major achievements, Qin Ke felt that it was necessary to contribute.

"Can I use the whiteboard?" Qin Ke raised his hand.

Academician Guo Weiyang was a little surprised, but he still nodded and said, "Yes."

Qin Ke walked to the big whiteboard in the conference room, picked up the erasable writing pen, and said while writing: "I have been following the seniors and seniors to do research and simulation experiments on this task for the past few days, and found that everyone is using NS The special solution of Equation No. 103, this special solution is indeed the most commonly used in the study of aerodynamics, but as the air thinner increases, it is difficult to accurately describe the rarefied gas using the linear constitutive relation of the NS equation of this special solution transport properties."

A formula soon appeared on the big whiteboard: "veff[▽u+▽u^T]=▽*(veff▽u)+▽veff(▽u)^T".

"I suggest changing to a non-Newtonian fluid to improve the ordinary equation of NS, so that the surface tension expression of the aircraft is more accurate. At the same time, because the high-order nonlinear constitutive relationship will make the numerical solution more complicated, I also suggest using the gas dynamics of solving the Boltzmann model equation The unified algorithm of scientific theory, and solve it by integrating the macroscopic values ​​such as stress tensor and heat flow, just like this..."

At the beginning, Qin Ke's brain was a little slow due to sleepiness, but as he focused on thinking, he wrote faster and more smoothly, and soon the entire whiteboard was filled with complicated and difficult mathematical calculations, and everyone in the audience began to write. He was still nodding repeatedly when he heard it, but when he got back, his expression was dull, and he began to look at each other in blank dismay.

Qin Ke didn't notice the expressions of the people behind him. He was excited to write, then pulled a large whiteboard, and continued to write more than a dozen calculation formulas:

"Look, through such a numerical transformation, the gas dynamic theory coupling method that can correct the constitutive relationship of the NS equation under specific conditions, and through the stress tensor and heat flow obtained by GKUA, the flow simulation with local rarefaction effects can be realized. Up to here Mathematical modeling can be carried out in one step. Using the compressible flat plate boundary layer and the numerical simulation of the flow around the cylinder can accurately deduce the experimental effect and reduce the number of experiments. It will be easier if the complete simulation can be realized with the help of supercomputing. After the accurate surface tension value is obtained, the shape change of the aircraft can be reversed, and improvement suggestions can be drawn."

You're done!

Qin Ke put down the erasable writing pen contentedly, and looked back at everyone: "My suggestion is this. If it goes well, we can complete this task in about two weeks at most, and then have a relaxing Spring Festival, right? It's very simple? Do you all understand?"

Quiet, the conference room fell into an enigmatic silence. Except for Ning Qingyun who nodded lightly with clear eyes, the rest of the people, including Academician Guo Weiyang, all had a bit of a stiff expression, looking at the big whiteboard as if they were looking at a heavenly book.

Is this the usual painting style of the Philippine Award boss?
As an elite group in the entire research group, and as a master of physics who has studied the NS equation for three years, at this moment, I have some doubts about life, and even doubt whether my three years of studying the NS equation have been lonely...

Seeing everyone's expressions, Qin Ke couldn't help scratching the back of his head.

do not understand?No way?He looked at the whiteboard again. His writing should be very clear. Anyone who is a doctoral student majoring in mathematics can understand everything. There are gains... Uh, Qin Ke turned around and looked at the crowd, and suddenly remembered that the people in the audience seemed to be Ph.D. graduates in physics...

Academician Guo Weiyang coughed lightly, breaking the awkward silence of the conference room: "I think Qin Ke's suggestion is very good...it makes sense, um...this...or, the specific mathematical modeling and experimental plan, just Qin Ke and Ning Qingyun will complete it? Xiao He, you are in charge of the supercomputing application process, and the rest will cooperate with Qin Ke to complete the entire experiment. If you don’t understand anything about Qin Ke’s explanation today, please ask Qin after the meeting gram."

Everyone nodded again and again, and then clapped vigorously.

Although I can't understand it, Qin Ke is full of confidence, and the formula he wrote looks very powerful at first glance. Solve the problem in two weeks... After a good year, think about it, it will not be a loss.

Thinking of this, everyone looked at Qin Ke with inexplicable awe and admiration.

(End of this chapter)