Chapter 153 Multi-body Dissipative Particle Dynamics
“It sounds like... it’s really feasible?”
“If it can be done, then our aircraft will be awesome...”
“…”
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 be able 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 are not very proficient in mathematics and physical theory.
And speaking from 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 given the conditions in Nanzheng. Can stay.
It’s not that the geographical and climatic environment of Nanzheng is not good, the key is the scientific research conditions. Who can stand it if one is outstanding and the other is not available?
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, General Master 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 our main wing and horizontal tail, so that we can conduct 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 It’s understandable if you think about it.
Proficiency in using computers and proficiency in using computers to draw are, after all, two different concepts.
As large 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 Chang Haonan. Seven with Yao Mengna in the past.
The entire computing center is deserted.
It wasn’t 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 same team. It's just the starting level.
Many older engineers may be able to learn to use computers, but it is difficult to make fundamental changes in their engineering thinking.
The talent gap in Factory 182 is serious. Today’s main force is either too old or too young. In this era of great technological change, we will definitely encounter some difficulties.
“It’s okay to be a little less skilled, just 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 it may have to be completely overturned later."
...
Although the technical foundation of Factory 182 is relatively weak , but it is still worthy of recognition in terms of work efficiency.
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 who met for the first time shook hands.
“I wonder who this is...”
Besides 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 and studies 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."
"Well, 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 twenty minutes briefly introducing himself. Ideas for wing ice accumulation prediction.
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 gently to indicate that it didn't matter.
“It is theoretically possible 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. It's reasonable, but 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 aspect, so they can do it right away. Consider many details unknown to laypeople.
“When an aircraft encounters moist and cold air during high-speed flight, the first problem is the impact of droplets on a rough solid surface.”
“Although it is true that the VOF or LSM method can be used to calculate the Euler net The calculation can be performed on the wing surface after grid or Cartesian grid processing. However, for large deformation problems such as high-speed impact, the numerical simulation system cannot guarantee that a well-posed interpolation function can be constructed on all grids, even if it is forcibly completed. In this step, when the mesh is deformed, it is difficult to ensure that the deformed mesh is not singular.”
"Not to mention that if you want to find a numerical solution to the N-S equation in this situation, the amount of calculation is quite exaggerated. Even if you use supercomputing, it will probably take several years to complete."
Lin Guofan said a lot. After finishing, Zhu Lan, who was 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.
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 just seen it wrong.
"Oh, Professor Zhu was right just now. I do have a new idea to calculate the surface interaction of liquid-solid high-speed impact."
"Huh?"
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.
Actually, Chang Haonan did not.
He really almost overturned just now——
Although he has accumulated 260 scientific research points by completing several major projects in succession 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 only 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.
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 foundations are both N-S equations. There are indeed some flaws when cold liquid droplets freeze after impacting with solids.”
“But we can completely change our thinking and use multi-body based on Newtonian mechanical equations and dissipation-fluctuation theorem. The dissipative particle dynamics method is used to conduct numerical simulation research on this problem. ”
"I don't know...What do you think, Professor Zhu?"
(End of this chapter)