The Military-industrial Scientific Research System of the Academic Master Chapter 153

Chapter 153 Multi-body Dissipative Particle Dynamics

 “Sounds like... it's really possible?”

“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 something, doesn't mean you know how to do it.

Just like answering questions in middle school, it is one thing to be able to understand the answers, but it is another thing to be able to do it yourself next time you encounter it.

Most people with ordinary engineering backgrounds are not very proficient in mathematics and physical theory.

From an objective reality perspective, 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 them given the conditions in Nanzheng.

It's not that Nanzheng's geographical and climatic environment is not good, the key is the scientific research conditions. Who can survive if one thing is outstanding and the other is not available?

 So it is still necessary for Chang Haonan to complete the previous part of the model algorithm, 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:

“Help me find a few people who are skilled in computer graphics. It doesn't need to be 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 including myself, I'm afraid not many people are proficient in computer graphics."

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

 Being proficient in using computers and being proficient in using computers to draw are, after all, 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.

For many older engineers, they may be able to learn to use computers, but it is difficult 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.

“It's okay to be a little less skilled. It's just a 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 seriously and meticulously. This kind of basic work must not go wrong, otherwise the whole thing may have to be overturned later.”

Although Factory 182 has a relatively weak technical foundation, its work 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 is invited from outside the aviation system and has long-term cooperation and is authorized to access classified military-related projects, it is impossible to just 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 who met for the first time shook hands.

 “I don't know who this is...”

Beside Lin Guofan, there was another woman who looked less than forty years old.

“I am Guofan's lover, Zhu Lan, who is also a professor at Jincheng University and studies surface physics. I heard from him that your topic this time is related to my research direction, so I 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 thoughts on the prediction of 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 to Liang Shaoxiu and others, Lin Guofan and Zhu Lan are much more proficient in this area, so they can immediately take into account 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 is deformed, 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 N-S equation in this case, the amount of calculation is quite exaggerated. Even with supercomputing, it may take several years to complete.”

Lin Guofan finished a long paragraph, and Zhu Lan next to him helped her husband to smooth things over:

“Perhaps Comrade Xiao Chang has 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, what Professor Zhu just said is right, I do have a new idea to calculate the surface interaction of liquid-solid high-speed impact.”

"ah?"

This time 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.

 Actually, Chang Haonan did not.

 He really almost overturned the car just now—

Although I have accumulated 260 scientific research points by completing several large projects in succession after my rebirth, people are always greedy.

In addition, Chang Haonan has indeed completed a lot of projects by his own ability in the past few months without relying on the system, so he began to think about whether he could gather the wool of 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 time is urgent and you 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. 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 the general research direction without going 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.

 The result...

Of course, he decisively spent 30 points to restart the plug-in, and then used a light cough to cover up the momentary abnormality that his brain showed when it 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 basis is the N-S equation. 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 dissipation-fluctuation theorem.”

“I don't know...what do you think, Professor Zhu?”

 (End of this chapter)

Chapter end