The military-industrial scientific research system of the academic master.

It was Yao Mengna who asked the question.

She just felt like she was back to that night when she just met Chang Haonan, when he explained with a flat face why the CFD method could not be used to simulate the vibration problem of straight wings.

Yao Mengna once thought that after such a long period of hard work, at least she would not encounter such embarrassing scenes again.

But obviously she still slightly overestimated herself.

When the subject extended to another field, the distance between the two seemed to be suddenly widened again.

“It really doesn’t work with traditional methods.”

Chang Haonan rotated the blackboard 180° to the other side.

In fact, even he had just sorted out his ideas about using the discrete element method to numerically simulate soft abrasives, and he had tried it out through the system.

[Based on discrete element theory, establish a three-dimensional model of abrasive particles, set the size, shape, concentration and density of the model, consider the coupling effect between fluid and abrasive particles, and establish abrasive particles and abrasive particles, abrasive particles and fluid, abrasive particles The contact model with the inner wall surface simulates the force and movement of abrasive particles in the fluid, predicts the movement rules of discrete phase abrasive particles, analyzes the removal mechanism of workpiece material by abrasive particles during abrasive flow polishing, and predicts the effect of abrasive flow polishing... 】

Although the discrete element method has been created in the 70s, the attention it has received so far is basically limited to the field of geotechnical engineering, and is far less widely used than the continuous element method.

The result is naturally a success.

[Technology points consumed to improve the project: 25 points. Points consumed to directly provide project results: 250 points. Are you sure to carry out the research project: Soft abrasive polishing and material surface removal mechanism based on discrete element method? 】

This time, Chang Haonan did not hesitate for too long before choosing to confirm.

On the one hand, this is not an area that he is good at, and more importantly, due to the technical zero principle that triggered quality problems, not only the production of the turbojet 14B, but also the turbojet 14A has been temporarily stopped. Now he is preparing to The four batch 4 J-00Cs delivered to the troops for trial have already started work in the workshop of Factory 8. No one wants to see the completed airframe unable to be delivered because it has to wait for the engine.

On the other hand, the control theory paper published on IEEE Transactions on Automatic Control allowed him to directly obtain up to 100 scientific research points and 2500 theoretical experience points, so there is no harm in splurging on the points.

In an instant, a huge amount of knowledge and experience poured into my mind.

Even though he had experienced this many times, he was still fascinated by the full feeling of his body being filled.

Chang Haonan took a deep breath, raised his hand to gently support his swollen head, and at the same time pretended that nothing happened and continued:

"As we all know, whether it is the finite element method or the finite volume method, an important basic assumption is that the dielectric material under study is in a continuous state."

"Under this assumption, the physical properties of materials can be expressed by continuous functions. These functions that express physical properties are usually called physical equations. By combining the physical equations of the material, the equilibrium equation of the problem, the boundary conditions and the initial conditions, we can Obtain the governing equations of the problem and obtain numerical solutions under specific conditions.”

“However, this type of numerical method has great problems when dealing with bulk materials composed of a large number of solid particles, because each particle in the granular material moves independently, which means that each unit node is likely to undergo large deformations. and displacement.”

"But we can completely change the perspective and focus on the detailed description of the contact behavior between particle objects, between particles and boundary models, and the overall balance relationship, which is discrete element thinking."

"Relate the contact behavior between objects with the momentum balance equation of the system, establish a differential equation of motion for each particle unit, and the motion equations of all particles describe the overall motion law of the discrete system."

"The main research process, I currently judge, can be divided into four steps. The first is to use mathematical language to describe the surface shape, movement and wear of the boundary model, and the second is to make a judgment on the contact between the particles and the complex boundary model..."

Chang Haonan talked about some basic theories for about twenty minutes, and then found that most of the people below were looking at him with clear eyes.

Fortunately, there are still a few younger engineers, and Yao Mengna is thinking seriously, and it seems that she understands at least part of it.

that's enough.

Similar to the situation at Institute 601, there are not a few people who need to cooperate with him in numerical simulation work. More people still have to be responsible for specific equipment development work, that is, to actually design and manufacture an adaptive software. The abrasive grinder comes out.

"As for the issue of discrete element simulation, interested comrades can talk to me in detail after the meeting. I probably need 3-4 people to help me with the programming and numerical analysis process."

"As for the remaining machine tool design part, I think we may need to find some external help."

After all, the main business of Factory 410 is to build aircraft engines rather than produce machine tools. It is okay to let them make some technical improvements, but it is indeed a bit too difficult to build a new grinding equipment from scratch.

"This is not difficult."

Zhong Shihong, who saw the dawn of a solution to the problem, instantly became energetic:

"Shengjing No. 1 Machine Tool Factory has always been a cooperative partner with us. They should be more experienced in this area. In particular, the development of abrasives and control systems are completed by regular workers, and the rest is purely mechanical."

"As for the specific method of cooperation..."

Zhong Shihong lowered his head and thought for a while:

"I think the cooperation between the two factories is not enough. If this equipment can be developed according to Chang Gong's ideas, it will be a huge encouragement and promotion for the overall development of our country's manufacturing industry. It just so happens that it is the end of the year. so……"

"My opinion is to urgently apply for a project from above, called the 'Precision Plan'. The goal is to systematically improve the production and manufacturing levels of various manufacturing plants in our aviation industry system!"

Obviously, Zhong Shihong also has some ambitions hidden deep in his heart.

For him, even if the main person to complete this project can only be Chang Haonan, as the leading initiator and the head of the technical department of Factory 410, as long as it can be successful, the benefits will definitely be indispensable.

From a larger perspective, if this new finishing method can be quickly promoted, it can also solve the urgent needs of many brother units.

Although the original intention of proposing this idea is just to polish the inner wall of the air film hole, its application range is obviously very wide.

Even if we only consider the field of aviation manufacturing, there are a large number of variable-diameter pipe parts, such as fuel and oil pipelines, fuel injectors, air guide holes, etc. The production efficiency and yield rate of each type are difficult problems.

"Very good, then... let's do it."

Chang Haonan has experienced the benefits of doing this kind of project before.

Funds and manpower are sufficient, and various resources applied for are basically given priority to ensure a green light all the way.

More importantly, the personnel subsidies are very generous.

Even Factory 182 can give out a bonus of 410 yuan at a time, let alone Factory .