Chapter 153 Multibody Dissipative Particle Dynamics

"It sounds like... it's really feasible?"

"If it can be done, then our aircraft will be very powerful..."

"..."

After the previous explanation, Liang Shaoxiu and others also abandoned their skeptical attitude.

Of course, just because you understand it doesn’t mean you know how to do it.

It's like answering questions in middle school. It's one thing to understand the answer, but it's another thing to be able to do it yourself next time you encounter it.

Most people who are ordinary engineers do not have a high degree of proficiency in mathematics and physical theory.

And speaking from an objective reality, even if there are people who can truly integrate scientific theory and engineering practice and make innovations and breakthroughs, it will be difficult to retain Nanzheng due to the conditions in this place.

It’s not that Nanzheng’s geographical and climatic environment is not good, the key is the scientific research conditions. Who can stand it if one thing is outstanding and everything is lacking?

Therefore, Chang Haonan still needs to complete the previous model algorithm part, and then the engineers of Factory 182 will complete the subsequent testing, analysis and parameter adjustment process with a large workload.

"That's it, Commander Liang."

After explaining his basic ideas, Chang Haonan took two steps forward and put the pencil back on the table:

"You can help me find a few people who are skilled in computer graphics. It doesn't take too many, just four or five. Let's electronically design the main wing and horizontal tail first, so that we can do numerical simulations of related issues later."

However, Liang Shaoxiu looked troubled when he heard this question:

"This...I'll try my best. Even if I count myself, there are probably not many people who are skilled in computer graphics."

"..."

Chang Haonan was dumbfounded for a moment, but he could understand it after thinking about it.

After all, being proficient in using computers and being proficient in using computers to draw are two different concepts.

As big as Institute 601, the digital design team only had twenty or thirty people when it was first established. Later, as Lin Shikuan and others failed to achieve results, this number even dropped a little bit to the seven that Chang Haonan and Yao Mengna had in the past. indivual.

The entire computing center is deserted.

It was not until digital design and manufacturing proved to be of great value in the improvement process of the J-8C that some people were sent back to Lin Shikuan. So far, they have only returned to the original level.

Many older engineers may be able to learn to use computers, but it is difficult for them to make fundamental changes in their engineering thinking.

The 182 Factory has a serious talent gap. Today's main force is either too old or too young. In this era of great technological change, it will definitely encounter some difficulties.

"Then it's okay to be a little less skilled. It's just a good way to learn some experience. In the field of aircraft design, I will definitely take this path in the future."

"But the candidate must at least ensure that the work is done carefully and carefully. You must not make mistakes in this kind of basic work, otherwise you may have to completely overturn it later."

……

Although Factory 182 has a relatively weak technical foundation, its efficiency is still worthy of recognition.

Within a few days, according to Chang Haonan's request, Professor Lin Guofan, who had long-term cooperation with them, was invited from Jincheng University.

Even if an expert invited from outside the aviation system has long-term cooperation and is authorized to access confidential military-related projects, it is impossible for him to casually let him enter the data room that is almost being used as an office.

So Chang Haonan met Lin Guofan in a conference room with relevant information.

"Hello, Professor Lin."

The two people meeting for the first time shook hands.

"I don't know who this is..."

Next to Lin Guofan sat another woman who looked less than forty years old.

"I am Guofan's lover, Zhu Lan, who is also a professor at Jincheng University. I study surface physics. I heard from him that your topic this time is related to my research direction, so I also came here with the above application."

"Then, thank you both."

The three of them quickly ended their simple greetings, and then Chang Haonan put the information on the table and spent about 20 minutes briefly introducing his ideas on predicting wing ice accumulation.

The two professors looked at each other, and finally Lin Guofan spoke first:

"Comrade Xiao Chang, you don't mind if I call you that."

Chang Haonan shook his head slightly to indicate that it didn't matter.

"It does make sense in theory to calculate the phase transition through kinetic and thermodynamic means when the properties of supercooled liquid droplets or ice crystals and the parameters of the aircraft wing are known. I’m afraid there will be some difficulties in implementing it.”

Compared with Liang Shaoxiu and others, Lin Guofan and Zhu Lan are much more proficient in this area, so they can immediately consider many details that laymen do not know.

"When an aircraft encounters moist and cold air during high-speed flight, the first problem is the impact of droplets on rough solid surfaces."

“Although it is true that the VOF or LSM method can be used to calculate the wing surface after Euler grid or Cartesian grid processing, but for large deformation problems such as high-speed impact, the numerical simulation system cannot guarantee that it can be calculated on all grids. A well-posed interpolation function can be constructed. Even if this step is forcibly completed, when the grid deforms, it is difficult to ensure that the deformed grid is not singular."

"Not to mention that if you want to find a numerical solution to the NS equation in this case, the amount of calculations is quite exaggerated. Even with supercomputing, it may take several years to complete."

After Lin Guofan finished speaking, Zhu Lan next to him helped her husband to smooth things over:

"Or does Comrade Xiao Chang have any new ideas on the problem of liquid-solid surface interaction? In this case, we can exchange research content."

The atmosphere suddenly fell into an eerie silence for a moment.

Chang Haonan, who was sitting diagonally across from the couple, did not react immediately.

"Comrade Xiao Chang?"

Zhu Lan asked softly again.

Chang Haonan's daze only lasted for a very brief moment before he recovered, making Zhu Lan even doubt whether he had seen it wrong just now.

"Oh, Professor Zhu was right just now. I do have a new idea to calculate the surface interaction of liquid-solid high-speed impact."

"what?"

Now it was Lin Guofan and Zhu Lan's turn to be confused.

Especially the latter. What she just said was just to make her husband's rebuttal seem less blunt. She didn't really think that Chang Haonan would have any in-depth research on surface physics.

In the end, people really have it?

Thinking of this, Zhu Lan couldn't help but pay more attention to the young man in front of him, and his expression gradually became serious.

In fact, Chang Haonan did not.

He really almost overturned the car just now——

Although he has accumulated 260 scientific research points by completing several major projects after his rebirth, people are always greedy.

In addition, Chang Haonan has indeed completed many projects in the past few months without relying on the system, relying solely on his own abilities, so he began to think about whether he could gain some knowledge about the system.

After forming a closed-loop idea, if you want the system to provide more specific research methods, you need to spend scientific research points. If you are pressed for time and want to get the answer directly, you will even have to spend 10 times the points.

But before that, the system will make a judgment on Chang Haonan's idea itself. If it is not feasible, it will directly prompt that a closed loop cannot be formed. If it is feasible, it will ask whether to spend scientific research points.

And this "free" feature is actually priceless.

Because it can at least determine that the general research direction will not be wrong.

If the paid version system is a perfect tutor that responds to requests and provides guidance, then the free version system is a pure tutor who gives you a research direction and then no longer cares about you.

But it's better than nothing.

So this time, Chang Haonan used this method to confirm that his thinking was correct, and then prepared to see if he could solve a problem that was not his area of ​​expertise by himself and limited foreign aid.

What is the result...

Naturally, he decisively spent 30 points to restart the plug-in, and then used a light cough to cover up the momentary abnormality shown when the brain received a huge amount of information.

Then, he spoke again:

"As Professor Lin just said, the VOF method and the LSM method are based on the assumption of fluid continuity, and their physical foundations are NS equations. They do have shortcomings when dealing with the situation where supercooled droplets freeze after impact with solids."

"But we can completely change our thinking and use the multi-body dissipative particle dynamics method to conduct numerical simulation research on this problem based on Newton's mechanical equations and the dissipation-fluctuation theorem."

"I don't know...how do you feel about Professor Zhu?"