Thinking of this, Chang Haonan suddenly felt that the name Wei Yongming seemed a little familiar.

He was very sure that this was the first time he had contact with Qinghua University since he was reborn.

Then it should be someone who has heard about it in a previous life.

"Casting process test requires a lot of financial resources and time, and you know, these two are what we are most lacking now, at present, the United States, Japan and Russia, these first-mover countries have been studying titanium aluminum alloy for many years, we rely on traditional means to catch up with them in a short period of time, but at present, the decoupling means we use have basically come to a dead end, and the project team has a big disagreement in the follow-up route selection."

After a brief introduction to the current situation and the difficulties faced, Wei Yongming asked Chang Haonan with expectant eyes:

"Therefore, I want to ask you this time, with the current technical means, is it possible to complete the simulation of the casting process on the computer through numerical calculations like fluid mechanics or structural mechanics?"

Although he is only a master's student, his summary is clear and organized, and he is definitely deeply involved in the whole project, rather than a simple person.

His question even stumped Chang Haonan for a while.

In fact, this is not the first time the latter has faced similar problems.

From the previous celebration party at the three gates, Yan Zhongzhong mentioned that the Liming Plant plans to use 1Cr16Ni2MoN martensitic stainless steel to produce the blades of aeroderivative gas turbines by hot forging, but the interaction between the deformation, heat transfer and microstructure evolution of the material greatly limits the application of the finite element method in the hot forging process that needs to fully consider the influence of microstructure.

Some time ago, in the discussion on the Sea Star radar, Guo Lin also mentioned that a big problem faced by 14 is that under the influence of environmental loads such as solar irradiation, wind charge, and salt spray erosion, the antenna array will inevitably produce structural deformation, deteriorate the antenna radiation performance, and need to consume more power to achieve the same transmission power.

However, increasing the input power will bring greater thermal power consumption, in addition to wasting the precious electrical energy on the warship, the temperature-sensitive T/R components and array power supplies will also produce performance temperature drift, resulting in the change of the excitation current output of the T/R components, and further deteriorating the radiation performance of the antenna.

Although these problems seem to be unrelated, and the fields involved are completely different, the dilemma everyone faces is the same-

Compared with the aerodynamic and structural design of aircraft, which only needs to consider the influence of mechanics, they design more physical fields, and have a very close influence on each other, and for the current popular calculation and analysis methods, it is impossible to calculate and optimize so many physical quantities at the same time.

In the traditional calculation method, when the nonlinear condition is introduced, the calculation needs to iterate repeatedly between multiple systems of partial differential equations to achieve convergence, but the casting problem involves material nonlinearity, geometric nonlinearity and boundary nonlinearity at the same time, and the iterative efficiency is extremely low, so the calculation time needs to be measured in months or even years, and the final result has a high probability of divergence.

However, if these physics fields are separated and calculated separately, the coupling effect is ignored, resulting in a complete inability to fit the simulation results with the actual situation.

As far as the available technical means are concerned, there is no solution to this problem.

Therefore, what Chang Haonan has been trying to do during this time is to write a new and comprehensive multiphysics simulation modeling software.

But this requires a high level of theoretical support, at least beyond the current era.

It is also the reason why he is eager to raise the theoretical ability level of the system to LV3.

After taking some time to summarize the language, Chang Haonan gave his answer in a cautiously optimistic way:

"Traditional decoupling methods, including the newly developed indirect coupling methods, can only deal with weak coupling problems between multiple physics, and strong coupling problems cannot be directly decoupled, so it really makes little sense to continue to try in this direction."

"For example, the casting process you just mentioned will involve a fluid-structure interaction, which is only a weak coupling problem under the assumption of small deformations, because the runner will have an effect on the fluid, but in turn the effect of the fluid on the runner can be ignored, and such a problem can be solved by decoupling."

"But the casting process doesn't fit that assumption......"

Wei Yongming's eyes dimmed slightly, obviously, he hoped to continue to go on through numerical calculations.

Because this is the only way for Huaxia to achieve technological leapfrogging.

"Yes, but not completely hopeless."

Chang Haonan nodded:

"I'm working on a fully coupled solution, and if it goes well, then ......"

Multiphysics simulation, if summed up as a mathematical problem, is actually to solve a system of partial differential equations with a high degree of nonlinearity, but the overall difficulty should be okay because the engineering only needs numerical solutions and does not require analytical solutions.

In addition, in the original timeline, FEMlab was also renamed COMSOL Multiphysics in 2005 and officially entered the field of multiphysics simulation, which is 8-10 years in time, and the theory at the LV3 level should be enough to cope with it.

What's more, engineering software is a thing that always needs to collect data for version iteration, and it is impossible to expect the first release to be perfect, and even if the most basic mechanical and thermal coupling can only be made at this stage, it can be called a huge help for almost all industries.

"If it goes well, then there may be some phased results in the second half of the year."

He still didn't choose to open the champagne too much in the half.

Wei Yongming, who was still a little lost just now, suddenly became excited:

"So, we can continue to use numerical analysis to shorten the research cycle?"

If someone else drew this kind of pie, then he probably wouldn't give one of them.

But the words score who says.

Before coming to this trip, Wei Yongming had certainly done some homework.

From past experience, the "phased results" referred to by the general counsel are generally not phased.

It belongs to the kind that can be directly concluded when placed in a topic.

"Of course, or rather, that's what my ultimate goal is in terms of algorithms and control theory."

Chang Haonan smiled and nodded.

Life sometimes presents some wonderful symmetry.

For example, he spoke to three Yenching students just a few days ago.

Now I said it again to a student at Qinghua University.

"If you want to do a good job, you must first sharpen your tools, although waiting for half a year or so may cost you some time, but in the end it is worth it in exchange for higher efficiency."

In his previous life, as a scientific research dog doing projects, Chang Haonan chose the second half of this year as the time node, and naturally considered the actual situation faced by Wei Yongming and them-

At the end of the year, the scientific research project must submit a periodic summary report.

If he pushes the software until next year, the project team is likely to choose to return to the traditional route under schedule pressure and ensure that the report is at least easy to write.

Experiments are of course necessary, but experiments that lack theoretical guidance are indeed a little too expensive for today's China.

(End of chapter)