I really just want to be a scholar

Chapter 588 Turbulence and the Navier-Stokes Equations
Qin Ke and Ning Qingyun only went through a short adaptation period of two or three days because they had practiced in the laboratory of Professor Duan Yonggong, and also participated in the research work of Professor Hu Qingfeng, Professor He Liangfu, and Professor Copet from Deguo. After that, I became familiar with the study and life in the "Air Turbulence and Climate Prediction" research group, and began to devote myself to it, entering my own study career as a follower.

Their postgraduate studies are also different from ordinary postgraduates. Whether to go to the classroom or not is completely self-determined. However, most of the courses for postgraduates are relatively simple to them, and there are only a few elective courses or professional courses. If they are interested in the content, they will listen to it. The rest of the daytime, they basically stay in the "Air Turbulence and Climate Prediction" research group.

After a few days of familiarization, Qin Ke has memorized everyone's appearance and names, and made simple notes in private, recording everyone's age, personality, hobbies, and family situation.

In the evening, in the "Xiaowo No. [-]" study room of the two of them, Ning Qingyun watched Qin Ke make the form, and couldn't help asking in a low voice: "Qin Xiaoke, what's the use of recording these?"

Qin Ke saw that there were only two of them here, and the girl with a single ponytail was a little guilty, as if she wanted to cover him up, so he couldn't help being happy, kissed the girl's pink and smooth face, and said with a smile: "It's not worth it, though. It’s a good thing to publicize, but it’s not a bad thing to be seen, so you don’t have to be so nervous. I made a similar form when I was just in college, and you may not have noticed it.”

Qin Keling shimmered to open the form in the laptop, and Ning Qingyun, who was blushing, saw the form file of "Basic Class List", which also recorded the general information of everyone in the class except her and Qin Ke himself. information.

“Every time I come to a new environment, if I want to actively integrate into it, I need to chat more to get information, and I have to record everyone’s main points, including likes, dislikes, taboos, and simple family situations, so that I can get along well with the people around me. Well, avoid accidentally "stepping on mine". For example, if someone gets divorced, you have to judge his attitude towards this matter, whether he is optimistic or consider it a great shame. If he is optimistic, you can talk to him about the blind date show on TV Just kidding, if it is a negative taboo for others to bring up this matter, then in front of him, even when talking to others, try not to involve sensitive words such as blind date, marriage, divorce, etc. We learned these in the first semester of our freshman year In the human relations elective course, the teacher has mentioned it, right?"

Ning Qingyun nodded in admiration: "I did learn it, but the teacher didn't explain it in such detail, let alone teach us how to do it."

"Practice what you have learned, and improve interpersonal relationships based on theory. You can see that my form is more professional than the form I used when I was just in college. The 'Air Turbulence and Climate Prediction' research group is where we have to study for a long time. We don't have to Join the so-called internal faction and firmly be the direct descendants of Mr. Jiang, but we should also try our best to create a comfortable environment to make learning and scientific research more enjoyable, right?
Qin Ke thought this way, and he also did so. With his social skills and unique personality charm, and taking the initiative to invite guests twice, he quickly brought Ning Qingyun to get acquainted with the people in the research group , the crowd also lost a little unfamiliarity and scrutiny towards them, and a little more sincere enthusiasm.

Especially those doctors who are also interns, the age difference is only seven or eight years old, and most of them are simple-minded. Seeing that Qin Ke and Ning Qingyun, who are already world-renowned mathematicians and full-time researchers in the Department of Mathematics, are not in the slightest. Shelf, are very happy to associate with them.

For example, Deng Zhaoliang, an extroverted postdoctoral fellow, is very enthusiastic about Qin Ke, and has been actively introducing him to various experimental equipment and the situation of several groups in the research group.

Deng Zhaoliang can also be regarded as a returnee, a Ph.D. in physics from MIT, one class later than Chen Licheng, who studied in the Department of Mathematics at MIT, but he has a good relationship with Chen Licheng. Last time, Qin Ke saved Chen Licheng's life. Deng Zhaoliang was very grateful. Shi was naturally very close to Qin Ke.

Of course, the boys are still a little nervous when facing Ning Qingjun, who is beautiful, youthful, and always faintly cool, and they are too shy to get close to him, but they quickly become shoulder-to-shoulder with Qin Ke, and they can have some fun. Color jokes and even tell the truth about close friendships, too.

The girls also got along well with Ning Qingyun under Ning Qingyun's snack offensive (Qin Ke pointed out). Most of the research group were men, but there were also about ten girls, most of whom were doctoral students or postdoctoral fellows.

Sensing that the atmosphere around the laboratory had obviously become gentler, more relaxed and cheerful, Ning Qingyun had to admire Qin Ke from the bottom of his heart. He was thoughtful, enthusiastic, and skilled. It was unreasonable for such a Qin Ke to be unpopular.

This day was Friday, and the weekly summary report exchange meeting of the research group was held in the conference room on the sixth floor.

All members of the research group in the laboratory building must attend this kind of summary report exchange meeting. At the meeting, they mainly share their recent research results and problems encountered.

The minutes of the meeting are usually taken by interns, and then reviewed by a researcher. As a newcomer, Ning Qingyun naturally took on the job of recording.

She recorded very well, which surprised her researcher Yu Xiaoqing. Sister Qing asked in a low voice, "Xiao Ning, have you recorded before?"

"Well, I have done similar work in other research groups before." Ning Qingyun nodded.

Sister Qing gave her a thumbs up.

Both Qin Ke and Ning Qingyun listened carefully in such a meeting, and learned many details that were not available in books.

For example, researcher Zhuang Huichao made a speech: "Recently, we encountered a problem in our group. When using the semi-Lagrangian method to calculate the advection term and discretize the space, if the central difference of the second-order accuracy is used, it will lead to the Grange upstream point. The solution dilemma, as well as the lack of conservation caused by the interpolation of upstream point variables, if the accuracy is further improved, the current service computing capabilities in our computer room will not be able to keep up, and we need to apply for Sunway TaihuLight’s supercomputer to calculate the data..."

Qin Ke looked through the information and found that the annual increase in the amount of data in the research group has exceeded 30TB, and it is also showing a trend of accelerating growth.

No wonder you need to use supercomputing. This amount of data cannot be handled by ordinary server groups.

Qin Ke hurriedly flipped through the information and put it aside, continued to listen carefully, and jotted down some issues that he thought were necessary to continue to search for information or worthy of attention.

The exchange of reports continues.

"Recently, we tried to use radar echo data to conduct short-term precipitation forecast tests..."

"Now that our experimental data is getting larger and larger, it is too inefficient to extract information by manually writing algorithms. I suggest introducing artificial intelligence to automate data analysis and information extraction..."

Artificial intelligence analyzing ocean data?This is a good direction.

Qin Ke thought of LV3's Shimmer. With Shimmer's data analysis and screening capabilities at this time, it is still very difficult to deal with such a large-scale data. Highly intelligent data analysis, data drawing and data forecasting and early warning, I am afraid that it will be LV4.

Just as Qin Ke was thinking about it, Jiang Weixian, an old academician, suddenly said: "Qin Ke, you have written a paper on climate phenomena under extreme weather before, and you can talk about the factors that affect the climate, as much as you can think of."

Qin Ke was taken aback, why did he suddenly ask a question?

However, this should also be regarded as a part of postgraduate study. With Qin Ke's physical knowledge reserve at this time, such a simple question can be answered with his mouth, not to mention that he had read a lot of literature in order to write a thesis.So he almost didn't even think about it and replied directly:
"There are many conditions that affect the climate. Different regions and different terrains will have different effects on the climate under different conditions. These are all natural geographical factors. In addition, there are global warming, glacier melting, El Nino phenomenon, sea level rise and other world Natural factors will also affect my country's climate to a certain extent. Physical and chemical factors produced by human activities will also have a significant impact on the local climate, such as vehicle exhaust emissions, chemical pollutant emissions, and human transformation of terrain and landforms. In addition, the turbulent effects of atmospheric motion on the surface can also have unpredictable effects on climate."

The old academician Jiang Weixian nodded slightly, then turned to Ning Qingyun and said, "Turbulence occurs at a large Reynolds number. Xiao Ning, can you briefly talk about the relationship between Reynolds number and turbulence?"

Ning Qingyun thought for a while and replied: "When the Reynolds number is small, the flow is laminar, because the viscous force has a greater influence on the flow field than the inertial force, making the fluid flow relatively stable. If the Reynolds number is large, the opposite is true. The hysteresis force has less influence on the flow field than the inertial force, and when the flow velocity exceeds a critical value, the fluid flow will become unstable due to the flow velocity, resulting in random motion in all directions, forming a chaotic and irregular turbulent flow field (vortex).

Academician Jiang Weixian nodded again. Of course he knew that these two students could answer the questions, but he just wanted everyone to see for themselves his disciple's solid basic skills.He looked at the two of them: "You should already be familiar with the situation of this research group. The research group is also divided into five groups. From today on, you two will follow up the research of the turbulence group."

There was a slight commotion around, but it soon quieted down, but the gazes towards Qin Ke and Ning Qingyun became complicated, with regret, sympathy, expectation and envy.

After the meeting ended, everyone dispersed and returned to their seats. The postdoctoral fellow Deng Zhaoliang next to him whispered to Qin Ke, "It seems that Academician Jiang has high expectations of you, and he actually asked you to study turbulence."

The so-called turbulent flow refers to the highly variable, multi-scale and irregular complex nonlinear fluid motion state in time and space.

Reynolds, a physicist from Eagle Country, was the first to discover and study the phenomenon of turbulence in fluid motion, and defined two flow states with completely different structures inside the fluid: laminar flow and turbulent flow, which is what Ning Qingjun answered just now Answer.

If there is any part of fluid mechanics that is the most difficult and complex, apart from the NS equations that span mathematical physics, it is turbulent flow.

Because turbulence is irregular and chaotic, if you express the turbulence of a small section of river with functions and draw it as a graph, you will see... what is a mess, just like a child scribbling and scribbling? A pile of lines makes one's scalp tingle.

If fluid mechanics is a pit, then turbulence is an abyss with no bottom.

Werner Karl Heisenberg, a well-known physicist in China, the founder of quantum mechanics, and the Nobel Prize winner in physics, once said: "If I see God, I will ask him two questions: What the hell is relativity? What the hell is turbulence? I think he'll know the answer to the previous question."

This great physicist in quantum mechanics studied turbulence before studying quantum mechanics. The title of his doctoral thesis was "On the Stability and Turbulence of Fluid Flow". However, one year later, he wisely discovered that turbulence is a difficult problem. In the abyss of the results, he decisively changed his career to study quantum mechanics, and won the Nobel Prize in Physics eight years later for his research results in quantum mechanics.When he was old, he became famous and tried to return to turbulence research with great ambition, but he still didn't make much progress, and finally gave up again, so he had the above sighing words.

——God will know the answer of relativity, but not the answer of turbulence.

Deng Zhaoliang was probably afraid that Qin Ke and Ning Qingyun would be frightened by his words. Seeing that they looked at each other, he quickly added: "The 'Turbulent Group' is known as the 'Elite Group' in our research group, basically only those who perform well Only members of the group are eligible to enter, currently there are only 19 people, including you, there are 21 people, and the group leader is Academician Jiang himself. The research on NS equations in the research group is also mainly in the 'turbulent flow group'."

As he spoke, he lowered his voice again, and said mysteriously: "Do you know about magnetic confinement controllable nuclear fusion? The turbulent flow group is also studying related key issues - the instability of magnetohydrodynamics caused by turbulent flow phenomena."

He sighed: "Because this group is too high-end, we respect it at a distance, and hope to enter this group one day, because it means that our strength has been recognized by Academician Jiang, and we have become the elite in the research group. Do you know the relationship between NS equations and turbulent flow?"

Qin Ke smiled and said: "I understand a little bit. To describe the turbulent flow phenomenon through the NS equation, it is replaced by mathematical language: whether the determined nonlinear partial differential equation has a long-term irregular asymptotic solution. Laminar flow is the NS equation at a small Reynolds number. The only solution to the initial boundary value problem. As the flow Reynolds number increases, the flow changes from laminar flow to turbulent flow. This can be seen as the nature of the solution to the initial boundary value problem of the NS equation. When the Reynolds number increases to the critical point, the NS equation bifurcates solution, the turbulence phenomenon is the asymptotically irregular solution of the NS equation."

Deng Zhaoliang was stunned when he heard this, and then gave a thumbs up after a while: "As expected of Academician Jiang's student, I admire, admire, if this is called a little understanding, then I think we doctoral students can be autistic collectively .”

From this day on, Qin Ke and Ning Qingyun joined the Turbulent Team.

Unlike other groups, the turbulent flow group does not need to leave the laboratory, nor does it need to run around for investigation, because most of the research work is done through theoretical derivation and small-scale experiments.

Qin and Ke haven't achieved any grades in physics for the time being, but old Mr. Qiu from Qiuzhen Academy has already called to invite them to start preparing for lectures.

At the same time, in the Lime Plant Cultivation Laboratory, where all the experimental equipment has been deployed, the research on computational seed science and seed DNA is also in full swing...

Of course, what attracted the attention of the international mathematics community the most was IMU's key review of Qin Ke's proof of the Riemann Hypothesis.

(End of this chapter)