stonecrandall Chapter 581
Chapter 581
Seeing Wang Defa, Zeng Xinghua and a group of project staff all gathered together.
Xu Hao simply handed the notebook in his hand to Wang Defa, asking them to take a good look at the problem.
Anyway, it is not time to start the work officially yet.
Clarify the cross-media dynamic modeling problem of cavitation fluid-solid coupling.
There are only benefits and no harm for these researchers.
It is even beneficial to the progress of the project work to a certain extent.
However, this made Xu Lanjie, who was already shy, even more uncomfortable.
He did not expect that he was just here to ask a question.
He actually attracted so much attention.
Realizing that Xu Lanjie seemed a little embarrassed, Xu Hao smiled slightly.
He nodded to him and gave him a relieved look.
At this time, Wang Defa, who was carefully checking the problem, frowned slightly and exclaimed softly.
"Huh? This problem seems to be really not simple."
"This mathematical model is a very complex coupled motion equation, involving dozens of hydrodynamic coefficients."
"It seems that it can't be solved in a short time!"
While speaking, Wang Defa raised his head to look at Xu Hao, and then at Zeng Xinghua.
He frowned, looking thoughtful.
Zeng Xinghua beside him did not respond, but picked up the pen he brought with him.
He did some calculations on the blank space in the notebook.
Then he shook his head helplessly and agreed.
"It is indeed difficult. I should not be able to get a definite solution and result in a short time."
"And there should be more than one error involved in this incorrect mathematical model."
"The result is quite different from the dynamic model in the design plan."
"It should be said that this is a relatively difficult problem!"
As soon as Zeng Xinghua said this, there was an uproar at the scene.
Wang Defa said it was difficult, and Zeng Xinghua also said it was difficult!
This is very rare, even in the past half month of work, there are few such scenes!
For a while, the curiosity of many researchers was even greater.
They came closer to check or ask.
What kind of problem was it that Wang Defa and Zeng Xinghua, two deputy project engineers, could not solve it in a short time!
Soon after, many people learned about the cross-medium dynamics modeling problem proposed by Xu Lanjie.
For a while, everyone's faces were different, and the voices of discussion were one after another.
"Hiss... It's really not easy! Why didn't I realize that dynamic modeling is so difficult before?"
"The main reason is that the force conditions of the cross-medium aircraft involved are too complicated, including the viscous position force, viscous damping force and inertial force of the ideal fluid, etc., and dozens of hydrodynamic coefficients are involved!"
"Tsk tsk, my scalp is tingling just thinking about it. I don't know how Academician Xu correctly modeled it at the beginning!"
"Forget it, forget it. My head is about to explode if I think about it anymore. The problems that Professor Wang and Professor Zeng think are difficult are definitely not something I can solve."
"Sure enough, it's comfortable to use it directly. If we were to model it ourselves, I'm afraid the project would have to be postponed for several months."
"..."
After checking it out, many researchers immediately understood the difficulty of this problem.
The complexity is simply amazing.
To unravel such a complex situation and find the problem in the wrong mathematical model.
It's really not something that ordinary people can accomplish!
Listening to the discussion of the people around him, and then looking at Wang Defa and Zeng Xinghua frowning.
Xu Lanjie opened his mouth slightly and couldn't help swallowing his saliva.
Is this problem really that difficult?
No wonder he couldn't make it consistent with the example in the design plan after trying more than a dozen times.
The problem is, since Professor Wang and Professor Zeng can't solve this problem.
Will Academician Xu also find it difficult?
Thinking of this, Xu Lanjie pursed his lips a little angrily.
He couldn't help but worry whether he would raise a problem that Xu Hao found difficult.
It's a small matter if it can't be solved in a short time.
But if Xu Hao loses face in front of so many people.
Even if he doesn't care, Xu Lanjie will feel very sorry.
Thinking of this, Xu Lanjie suddenly frowned.
He couldn't help but look at Xu Hao not far away.
Unexpectedly.
Xu Hao did not frown like Wang Defa and Zeng Xinghua and fell into deep thought.
Instead, he looked at everyone with a smile, as if he was observing whether anyone could solve the problem.
Seeing this, Xu Lanjie was slightly startled and couldn't help but feel a little confused.
It doesn't look like he thinks the problem is difficult!
At this time, Xu Hao, who saw that no one had any ideas about this problem in a short time, stepped forward.
He coughed lightly to showHe made sure everyone was quiet, and then he started to explain.
"Everyone, pay attention. Obtaining the hydrodynamic coefficient is the key to solving the cross-media aircraft dynamics model."
"The error model here uses the hydrodynamic parameters obtained by theoretical calculation and model experiment."
"Although it is feasible, it is easy to produce errors and has certain limitations."
"And the cross-media dynamics model constructed in the design plan uses parameter identification algorithm technology..."
Listening to Xu Hao's talk, Xu Lanjie was stunned at first.
Then he reacted immediately and hurriedly took out a pen and paper from his pocket.
While listening carefully, he copied down the key points and problems pointed out during the explanation.
At the same time, he smiled bitterly in his heart.
I really thought too much just now. Others think it is difficult, but it does not mean that Academician Xu also thinks it is difficult.
Xu Lanjie even suspected that Xu Hao might have noticed the problem and thought of a solution when he just glanced at it.
Not daring to think deeply, Xu Lanjie waved away all the thoughts in his mind.
Facing Xu Hao's focused gaze, he listened and recorded confidently.
Not only him, but many scientific researchers, including Wang Defa and Zeng Xinghua, were listening attentively at this moment.
They dared not be distracted by any word.
At the same time, according to the many questions raised by Xu Hao and his own inner thoughts, he could not only check for deficiencies and make up for them, but also quickly summarize the deviations and fallacies in his own thinking.
The whole workshop was completely different from the noisy scene on weekdays.
Only Xu Hao's voice could be heard.
"The above is one of the problems that cause the wrong model, which needs attention."
"Secondly, we should focus on several characteristics that are easy to affect the coupling analysis in the process of constructing the dynamic model."
"For example, due to the difference in density between water and air, the huge impact load caused by the initial entry into the water induces plastic deformation inside the aircraft."
"And in the process of the aircraft passing through the free surface, the change of its immersion characteristics will have a significant impact on the dynamic characteristics of the structure, etc."
"Here is ignoring the change of the dynamic characteristics of the aircraft structure, causing errors in the dynamic model..."