Ding Gaoheng, who had signed the letter, put the pen back in his hand, and when he raised his head again, he only saw Chang Haonan leaning on the sofa, looking at the ceiling with his eyes scattered, looking like he was wandering in the world.

This posture seemed to be thinking, so he didn't rush, just pushed the report to the corner of his desk, and then began to deal with other official business.

As a result, in the office of the director of the Commission of Science and Technology, such a strange scene appeared.

Ding Gaoheng was lying on the desk and writing hard, getting up from time to time to refill himself with a glass of water.

And on the sofa not far away, sat a young man with his eyes in the sky......

That kind of relaxed state, if you don't know it, you still think that there is a special relationship between these two people......

Fortunately, the afternoon was unusually quiet.

It wasn't until he was about to get off work that Chang Haonan got out of his thoughts just now.

"Xiao Chang?"

Seeing that he finally moved, Ding Gaoheng also breathed a sigh of relief.

"Oh...... Director Ding...... I just had some inspiration and thought about it......"

Chang Haonan sat up straight, and at the same time, almost subconsciously, raised his hand and stroked it on his forehead.

It turned out to be covered in sweat.

I'm really sweating now.

Naturally, the air conditioner was turned on in the office, but Ding Gaoheng was not young after all, and his physique was not as good as that of a young man, so it was impossible to blow at the lowest temperature.

Therefore, the temperature in the room was already a bit high for Chang Haonan, and coupled with the high-load thinking just now, it did bring a lot of load to the thermoregulation mechanism.

Fortunately, the system should have the ability to adjust automatically, except for the first moment, the "calculated power" has been turned on to a level that Chang Haonan can accept.

Otherwise, I'm afraid I'm really going to "I'm on fire!" ”。

But this also gave Chang Haonan a new idea-

If he really soaked in a bathtub of ice, would the efficiency of thinking be further improved......

"I saw it, so I was afraid of interfering with your train of thought just now, so I didn't call you."

Ding Gaoheng obviously also saw the sweat on Chang Haonan's face, got up and put a roll of paper on the coffee table:

"Wipe your sweat, the weather at the end of May is already a little hot......"

"Thank you, Director Ding."

Chang Haonan said a simple polite word, then tore off a few pieces of paper and folded them together and began to wipe his sweat.

"What were you thinking about just now, so distracted?"

Ding Gaoheng returned to his seat and asked casually while holding a teacup and blowing lightly.

"Hmm...... Graduation thesis thing. ”

"Huh?"

On the other side, Ding Gaoheng's action of fiddling with the lid of the cup stopped directly, and raised his head with a shocked face:

"You still have to worry about your graduation thesis?"

In his opinion, today's Chang Haonan can be called a big daddy-like existence for Jinghang, and it is too late to be a bodhisattva, how can he do something about graduation.

Besides, with the current situation, targeting Chang Haonan is aimed at him Ding Gaoheng, and going deeper, it is aimed at ......

There shouldn't be anyone who is so short-sighted.

"It's not the dissertation itself."

Chang Haonan shook his head and quickly explained:

"I just suddenly came up with some extended research from the content of my paper, about the ...... of using the principle of spatial averaging to correct the N-S equation."

In fact, Ding Gaoheng was just curious at first, so he just asked casually.

After all, the two of them have known each other for so long, and he has never seen each other think for so long.

There was no expectation of an in-depth discussion on this topic.

But the moment Chang Haonan's answer mentioned the N-S equation, he suddenly became interested:

"You've come up with a new way to solve the numerical problem?"

For anyone whose field of study is related to fluids, the N-S equation is an impossible mountain to bypass.

Since the current mathematical tools cannot find strict analytical solutions, how to obtain numerical solutions for specific problems more accurately and efficiently has become the focus of applied mathematicians and physicists in various countries.

It can be said that the TORCH Multiphysics software was able to achieve a cross-era lead in the field of fluid computing, which was largely due to the breakthrough made by Chang Haonan at the level of numerical solutions at that time.

Although some of the mathematical theories are public achievements, when it comes to application, it is difficult for others to keep up with the pace of optimization and iteration of the Torch Group itself, even if they take the source code to compare.

What's more, the Pro Plus version is not even public software, let alone the source code.

And if you do it again at this time......

What will happen, Ding Gaoheng didn't dare to think about it.

However, Chang Haonan's response was to shake his head:

"Not exactly ......"

This made Ding Gaoheng's excitement drop a little.

But think about it, a breakthrough of that level, once in a few years or even more than ten years, is already very remarkable.

Moreover, even further modifications at the level of the original algorithm can significantly improve the computational efficiency......

"I think that the inertial manifold of the two-dimensional N-S equation is universal."

Chang Haonan's second sentence choked back the words that Ding Gaoheng had already come to his lips.

"What?"

The latter's mind didn't keep up for a while.

"The inertial manifold of the two-dimensional N-S equation may be universal."

Chang Haonan repeated.

But it is obvious that Ding Gaoheng did not hear the Chinese characters clearly, but heard every word, but did not understand the meaning of the connection.

So he had to explain:

"To put it simply, because there is an affinity relationship between fast and slow variables, the direct neglect of fast variables and the retention of slow variables will lead to the loss of a lot of dynamic information in the process of dimensionality reduction of the nonlinear partial differential equation system. The purpose of all nonlinear dimensionality reduction methods, including my current research, is to improve the modeling accuracy without increasing the dimensionality of the reduced system, and to compensate for a part of the lost information. ”

"The inertial manifold is one of them, but because the fast variables that are ignored in the inertial manifold can be represented by the slow variables, the calculation accuracy and efficiency are much higher than in the traditional way in the past...... However, for most nonlinear partial differential equations, including the N-S equation, it is difficult to find the corresponding inertial manifold......"

"So we, uh...... That is to say, the TORCH Multiphysics software currently adopts two methods: one is to assume that the fast variable is in a pseudo-stable state, so that the approximate inertial flow pattern can be easily obtained by ignoring the dynamic information of the fast variable; Second, considering the loss of dynamic information due to the deletion of fast variables, the Eulerian method is used to calculate the integration of the deleted fast variables in a short time interval, and an approximate inertia manifold can be obtained......"

"However, both methods are essentially superimposed on the basis of approximation, so although the results are indeed better than the traditional methods, they return to the category of pure application, which is not very helpful for advancing theoretical research......

“……”

Ding Gaoheng is not from a mathematical background, not to mention that what Chang Haonan said is not even completely applied mathematics, but has already gone a little towards the theoretical part, so he just feels ...... after listening to it

This "to put it simply" is not simple.

However, although I didn't fully understand the specific content, the general meaning is still understandable:

"So...... You're wanting...... Get a global solution to the N-S equation? ”

This idea is a bit too self-indulgent -

If the N-S equation is really completely cracked, it is basically equivalent to reshaping the entire aerospace industry from the roots.

What wind tunnel, what pneumatic verification machine......

None of them are needed.

Just go straight to the prototype and put it into production.

"Ah...... No, no, no, it's not that exaggerated. ”

Chang Haonan hurriedly waved his hand:

"Although in terms of direction, it can indeed be said that it is a step towards solving the N-S equation, but it can only be regarded as the first ...... of the long march to truly obtain the analytical solution."

Speaking of this, he hesitated again:

"It's not just the first step, after all, it's a little bit further on the basis of pure numerical solving, but it's a bit ...... to say that the second step is Strictly speaking, step 1.5 ......"

(End of chapter)