Chapter 241: Aviation modification is also difficult (Part 2)
“In terms of numerical calculations, if we need assistance from our Computing Technology Research Institute, we can also provide some supercomputing resources.”
Xu Yang's voice is unfamiliar to everyone except Chang Haonan.
So Yan Zhongcheng looked at the opposite side and was stunned for a moment, and then replied:
"It would be great to have supercomputing resources, but the key to our progress is not the amount of calculation, but the software. Functional and algorithmic limitations ”
Now Xu Yang was really interested:
“How to say?”
“Although the core parts of aeroderivative gas turbines are ready-made, marine gas turbines and aerospace engines are in use environments. , performance trade-offs, cost control and other aspects are still very different, so it is not enough to copy them completely.”
Because everyone here is his own, Yan Zhongcheng gave a very complete answer:< br>
“For example, warships will have strict requirements on noise and vibration, especially if anti-submarine is the main mission target, it will be even more stringent, while aviation engines have relatively smaller restrictions in this regard.”
"Another example is that warships may sail in polar cold waters for a long time, and the gas turbine air inlet must overcome the icing environment. However, because jet aircraft are fast enough, there is almost no need to consider this problem."
" This part of the work also involves more than a dozen multi-physics coupling effects such as acoustic vibration, heat, and thermoacoustics. If we want to achieve accurate calculations through current simulation modeling software... on the one hand, it will be very difficult, and on the other hand, considering the current The calculation speed of our country’s supercomputer may take longer than building a few prototypes according to the old method.”
“And this is only a problem faced by the design stage itself. Good designers need to be in the process. The convenience and economy of subsequent production, maintenance, and repair work were taken into consideration during the design process. Because the gas turbine is not sensitive to its own weight but is sensitive to life and cost, Liming Factory plans to use 1Cr16Ni2MoN martensitic stainless steel to produce blades through hot forging. Then when designing, we cannot only focus on performance like aviation engines, but also consider the adaptability of blade size and shape to the process, otherwise it will cause problems for the manufacturer.”
“During the hot forging process. , the interaction between material deformation, heat transfer and organizational evolution greatly limits the application of the finite element method in hot forging processes that need to fully consider the influence of microstructure. It is also a complex multi-physics comprehensive interaction process... ”
Yan Zhongcheng is worthy of being one of the early explorers in the field of domestic computer simulation. Although he has been left behind by the times because he has not been exposed to the top international experience for a long time, he still can’t do it if he really wants to do it. Able to organize work in a clear and clear way.
This long paragraph first stunned Xu Yang, and then quickly inspired her fighting spirit.
Providing help but not being asked for it was definitely the first time for Xu Yang that a big girl got on the sedan chair.
“Although current software and algorithms do not support the simulation of such complex multi-physics fields, there are still many methods that can overcome this problem to a certain extent...”
She I thought that after raising this topic, I could attract the curiosity of other people, especially Chang Haonan.
But everyone seemed to have a mediocre response to this, and the main character lowered his head and fiddled with his chopsticks unconsciously.
In the end, it was Yan Zhongcheng who took over the topic so that there was no silence:
“I know how to split these problems into ordinary single field or dual physics field coupling to solve, but this requires a lot of work. For modeling and writing code, the rigid requirements for the amount of calculation are not that high."
"This..."
Xu Yang was a little surprised that the person in front of him looked like he was in his sixties. A young man actually has this ability.
She is actually a very pure person, so she immediately respected Yan Zhongcheng:
"Do you also do research on multi-physics modeling?"
"It's not much of a research. These technologies didn't exist when I was studying in the UK, so I didn't learn anything." Yan Zhongcheng said. Here, I turned my attention to Xu Yang’s side:
“Actually, this also requires Comrade Chang Haonan’s experience in the previous design improvement work on the turbojet 14, as well as his complete notes. I took advantage of my position and often read and thought about it, and gradually understood something further.”
“Dr. Chang?”
This was somewhat beyond Xu Yang's expectation.
Of course she knew Chang Haonan's level, but it was one thing to be capable, and it was another thing to be able to teach or inspire others.
In fact, the more talented people are, the less good they are at this aspect.
It's similar to letting Jordan be a coach -
You just need to take off and wait for the opponent to fall before shooting.
Chang Haonan, who was wandering in his mind, suddenly heard someone calling his name, and subconsciously raised his head:
"What's wrong?"
"I don't know, Dr. Chang, what do you think about this kind of polyphysics?" Do you have any specific ideas for field simulation modeling calculations? "
Although the current situation is not academic enough, Xu Yang still couldn't restrain his curiosity and wanted to hear the other party's thoughts.
On the one hand, it is to communicate with each other, and on the other hand, I also want to see who of the two is better at this aspect.
However, Chang Haonan shook his head directly:
“I don’t have any specific ideas, because the current tools actually only support the simulation of two-dimensional fields. No matter how exquisite the method is to split the specific problem, many variables will be eliminated. If you ignore it, the accuracy of the results can be imagined, and subsequent adjustments will need to rely heavily on experimental data and experience."
When he first heard this answer, Xu Yang felt a little disappointed for a moment.
But a deep intuition told her that Chang Haonan might not have finished speaking yet.
Sure enough, after a pause, the latter continued;
“For example, the classic phenomenological model that expresses flow stress through hyperbolas, and the high-temperature flow stress model that expresses material parameters as polynomials are purely mathematical models that do not consider the microscopic mechanism in the deformation process of metal materials. The influence of macroscopic deformation parameters such as deformation temperature, strain rate and strain amount on flow stress is known. Therefore, for each material, even if only one of the elemental components changes, it must be started all over again. ”
"What I was wondering was whether we could find a way, at least from a physical point of view, to describe the thermal deformation behavior of the same type of material and, further, develop a new tool, I mean a software, Realize three-dimensional finite element numerical simulation, such as establishing a deformation-temperature-structure evolution coupled analysis system for the martensitic stainless steel just mentioned, so that you can simultaneously study the effects of deformation parameters on the temperature field, strain field and microstructure field without splitting. The impact is obviously more instructive for actual production process design and optimization."
"Ah this..."
For the first time, Xu Yang felt that his ideas were thrown away by others. It's open.
Just like under the apple tree that influenced physics, while she was still busy picking apples, others were already thinking about why the apples fell from the tree...
(End of this chapter)