Chapter 931: Staying unchanged to cope with all changes
Time passes minute by minute.
Chang Haonan frowned slightly and stared at the computer screen.
In the huge office, there is almost only the faint "click" sound caused by the occasional rotation of the mouse wheel
Anthony Jameson's paper has a lot of content, but the length is It’s not long, in other words the content is a little jumpy.
If you are a reader who has not had much exposure to the finite volume method, you will most likely need to read it several times to understand its meaning.
Fortunately, although Chang Haonan is not specialized in this, he actually used the software COMSOL Multiphysics a lot in his previous life, so he has some understanding of the Swedish company's "problem-solving ideas".
"Huh——"
After about half an hour, Chang Haonan finally put down the mouse in his hand, leaned on the back of the chair and exhaled a breath.
Apparently I have finished reading it.
However, his frown did not relax.
This made Wei Yongming and Song Jingming not far away a little worried -
If Mr. Chang feels that it is difficult to deal with after seeing it, it means that the other party is really a little bit. thing.
After a few more minutes, Wei Yongming, who had not dared to disturb him just now, finally couldn't hold it in any longer -
Stretching out one's neck is the same as shrinking one's neck, no matter what the conclusion is. Okay, don't say anything...
Therefore, after hesitating for a moment, he tentatively expressed his doubts:
“Mr. Chang, I think Professor Jameson’s idea should be to apply the spectral volume method on unstructured triangular grids. To solve the hyperbolic conservation law, but I have conducted several calculation tests before. The spectral volume method requires a huge number of Gaussian integration points when calculating the control surface integral, which will increase the calculation time? ”
< br>As the head of the technical department, since Wei Yongming came to see Chang Haonan today, he naturally read this paper in advance.
It’s just that there are some contents in it that don’t seem to match the promotion of the other party’s products.
"The paper...is just a pure theoretical process."
Chang Haonan replied:
“From theoretical derivation to specific algorithm implementation, the details in between are the key to software design.”
“Just like my article introducing the conservation level set method The paper was also published in a journal, but others did not have matching grid generation and high-order partial differential equation dimensionality reduction techniques. Even if they understood the content of the paper, they could not apply it to the software. "< br>
“As for Jameson’s method, it should only draw on the idea of the spectral volume method. It does not directly apply the spectral volume method to unstructured grids.”
“Although the paper It does not involve the subsequent application level, but I speculate that they will choose to use the node function value of the spectral unit instead of the volume average to construct the discrete format. In this way, the LevelSet function value of the control volume boundary can use high-order Lagg The linear combination of Lange polynomial interpolation and second-order windward interpolation is estimated, and the total degrees of freedom and the number of Gaussian integration points will be reduced accordingly. This method is also in line with what COMSOL is good at..."
"..."
Facing the paper on the computer screen, Chang Haonan quickly deduced the specific technical route of the other party's algorithm through reverse thinking.
And Wei Yongming, who was sitting on the sofa, took out a small notebook at some point and was taking notes with his head down.
“Of course, this is just my speculation from a theoretical level, and it may not be 100% accurate...”
Looking at Wei Yongming who was writing vigorously, Chang Haonan still couldn’t finish his words in the end. , leaving himself a way out.
But this sentence obviously had no impact.
The movements of the former's hands even became faster.
Song Jingming next to him may have received too much content that he didn’t understand at all. At this time, he felt that his brain was a little bloated, so he took advantage of the gap where Wei Yongming had no time to raise his head and quickly changed the topic from technology. When it comes to management:
“Mr. Chang, in this situation, do we need to change the original planned update route?”
“For example... uh... use some newer ones. Technology to deal with it, etc.”
In his opinion, since Chang Haonan just showed a solemn expression, it obviously meant that the other party had indeed put enough pressure on him.
Of course, this is not entirely Song Jingming’s own idea, but a conclusion reached after discussing with Wei Yongming before this trip——
In the field of CFD, Torch Group actually There are still some unused technical reserves.
Mainly focus on high-precision methods.
It is just because of the development cycle that it cannot keep up with the original update schedule.
At present, if we want to continue to maintain Torch Group's advantages in numerical calculations, especially in the field of computational fluid dynamics, we must delay updates to introduce these more promising technologies.
However, Chang Haonan did not nod immediately. The update to version 2.0 of the TORCH Multiphysics software was something he started to prepare more than half a year ago, involving major improvements in three aspects: multiphase flow, topology optimization and CFD.
Nowadays, it can be said that we are only one step away from the launch of the new version. If you rashly disrupt your own rhythm because of the other party's actions, you will fall into passivity.
In fact, in the final analysis, it is still caused by backward data transmission methods.
In 2001, the main means of updating large-volume commercial software was still to physically mail storage media such as CDs or hard drives.
This means that users cannot accept too high an update frequency.
It also means that vicious bugs are completely unacceptable.
Because the cycle and cost of fixing bugs are unacceptably high.
Therefore, the software testing cycle these days is generally relatively long to ensure that there will be no big troubles.
And if, like more than 20 years later, the software can be upgraded online at any time, then you can push a 2.0.5 Beta version first, and then push the official 2.1 version after the new technology stabilizes.
Even if there are some bugs in the first version, they can be quickly corrected.
And, there is a more important point.
That paper.
Although Chang Haonan understood it and even guessed the opponent's general technical route.
But there were still some details that concerned him.
That’s right, he had been frowning just now. In fact, he was not worried about the threat caused by friendly businessmen to the Torch Group, but was thinking about these issues.
It was just misunderstood by the two people opposite...
...
After struggling alone for a few minutes, Chang Haonan raised his head again and answered decisively:
"Updated plan, unchanged!"
"No... unchanged?"
This decision was obviously beyond the expectations of the two people on the sofa.
“Yes.”
Chang Haonan nodded, then stood up and came to the window, looking at the city in the distance:
"On the one hand, we cannot be led by others. Even if the new version of COMSOL Multiphysics can achieve the effects they advertise in the CFD field, we still have advantages in multiphase flow and structural topology optimization, so users cannot be like this Abandon our software. ”
“So, the worst case scenario is that a considerable number of users start to use our two software programs separately for different problems. This result is not completely unacceptable to us.”
Speaking of this, he paused for a moment, then turned around and gestured in the direction of the computer screen:
"On the other hand, this paper only mentioned targeting N-S The equations are solved using the lattice-centred finite volume method discretization, but in actual operations, there is not much discussion on the high computational weight issues that are common in numerically solving viscoelastic constitutive equations. ”
“There is not much discussion about this type of problem. , the LCR method that has been much studied at present is to convert the original stress tensor evolution equation into an evolution equation in the logarithmic form of the conformation tensor matrix. This process requires the calculation of the stress tensor and the matrix logarithm of the conformation tensor. Repeated conversion of the form can easily cause loss of accuracy. If the calculation weight is too large, it may even cause the algorithm to collapse. ”
"Of course, it is impossible for a consultant of a commercial company to write down all the technical details when publishing a paper, but it is still too strange not to mention it at all..."
Chang Haonan touched his chin as he spoke.
Although this sentence has obviously not been finished yet, Wei Yongming is already a little unable to hold on:
“Mr. Chang, our group should not have researched the finite volume method as a key technology, right? ?”
“You...know so clearly?”
"Oh, it's clear that we can't talk about it."
Chang Haonan waved his hand and replied with an indifferent expression:
"When the Torch Group was not officially established, I wanted to give the new I selected a technical route for the software and read some relevant information, but I didn’t expect it to be useful at this time.”
“Anyway... they said they would push the update later this month, so it only takes two weeks. , let’s stay the same to cope with all changes. After their new version is released, we will see what kind of medicine is sold in the gourd opposite..."
(End of this chapter)