"yes, it doesn't look like there's a formula for the engine." An Zhusheng sighed casually. It's also a question that has plagued him for years. In addition to considering the nature of the fluid itself, the heat exchange between the fluid and the outside world, as well as the specific thermodynamic process in which the fluid participates, will affect the flow of the fluid. In fact, everyone understands the basic principle here, but the lack of specific calculation means and tools greatly limits the development of domestic work in this area.

"Actually, it's not impossible." Shen Yiyi's seemingly relaxed words suddenly attracted An Zhusheng's attention. He looked at Shen Yiyi with an incredible expression.

Shen Yiyi took out the piece of paper that recorded the derivation process she had just made, picked it up again, and pointed to a certain place in the derivation process: "Before here, this formula was completely applicable to any fluid. So temperature, density, or other factors do not affect the correctness of the previous formulas at this step. ”

"But from this point on, because we have this assumption, we have to take into account the temperature and other variables. So what do we do? When Shen Yi first started discussing the problem, her mind would easily indulge in what she was studying, so she didn't look at An Zhusheng anymore, thus ignoring the hopeful look in the old man's eyes.

"Let's make such an assumption, take into account the effect of temperature on the enthalpy of the gas, and then make a differential simplification...... Following Shen Yiyi's train of thought, her pen tip began to evolve from a certain place in the formula that was different from the original derivation process. This time, Luo Yu couldn't understand it again, but An Zhusheng's eyes showed more hope.

Step by step, step by step, Shen Yiyi's derivation was heard in An Zhusheng's ears. It can be explained in principle, and it is logically rigorous enough, so of course, it was affirmed by An Zhusheng's basic judgment at the time of writing. And An Zhusheng is more concerned about what kind of formula can he get in the end through Shen Yiyi's unexpected play at every step? If you get the formula at the end of the day, it's too computationally intensive. It also returns to the huge gap in computing power that China's engineering community is currently facing, and it still has no practical value.

Unlike An Zhusheng's ambivalence of high hopes and fear of the final result, Luo Yu looked at the formula newly pushed by Shen Yiyi, and sadly found that he still hadn't thoroughly understood the formula that Shen Yiyi talked about last time. He didn't even think about changing the conditions, changing the assumptions, this same formula. It turned out to be a different look. It seems that he still needs to master a lot of knowledge in the future, and he has to learn well during the winter vacation.

Shen Yiyi now has no time to pay attention to the psychological changes of the old and young around him. She is now very afraid that she will make a mistake in her deduction. So she's unusually focused on the letters she writes now. Of course, she can actually write a formula that can be applied to aero engines. Because the simulation formula was also derived from her backwards from a large number of examples. But the problem is that in the era of 1994, she had to explain the origin of this formula to people today, so as not to make others doubt her origins. Such high-tech and technically charged "counterfeiting" work requires extremely high tests on the theoretical foundation and psychological quality of the "counterfeiters."

“…… Consider that the latter terms here are all equivalent infinitesimals. So it can be omitted. So there are only a few items left in this formula. So let's sort it out and we can get such a formula. ”

Thankfully. Shen Yiyi's luck has always been good. She cautiously deduced the results step by step, and finally finally got the formula that she had actually wanted to write for a long time. The moment the formula came out, she couldn't help but take a deep breath and calm down before raising her head to look at An Zhusheng. She didn't expect that the old man who had always given herself a very high and unfathomable impression after seeing him. At this moment, she was very excited, and she was almost snatching the paper in her hand.

"Show me...... Look at ...... again," An Zhusheng couldn't hide the excitement in his heart. He was almost holding his breath watching Shen Yiyi's formula derivation at every step, and at the same time, his mind was spinning at high speed, always judging whether Shen Yiyi's derivation process had made mistakes. But, as he hoped, it was different from what he feared. Every step of Shen Yiyi's derivation is completely defensible in his common sense and intuition. And what excites him the most is that the formula that Shen Yiyi summed up after the most is quite simple in form, and even uses the general characteristics of scientific theories that he used to think, that is, it reveals a minimalist beauty. Such a formula, in his heart, must be a good formula. He checked Shen Yiyi's complete derivation of this formula from beginning to end again, and still found no problems. At this moment, his heart was really excited. This formula seems to have a play!

Of course, as a scholar, An Zhusheng also knows that the proposal of any theory should not only be based on whether it is correct logically, but more importantly, it should be tested with actual data. Similarly, although Shen Yiyi's formula has also been confirmed that there is nothing wrong with the derivation process, it must also be tested by test data before it can really show that this formula can be used. Old man An Zhusheng couldn't wait to take this formula back to the 606 Institute to test it.

He clutched the piece of paper tightly in his hand as if he was snatching a treasure, and said to Shen Yiyi: "Shen Yiyi, give me this piece of paper." I'm going to take it back and study it. Said that it was a pleading tone, but the tone revealed a firmness that did not accept rejection. Old man An has the advantage that you agree that I have to take it away, and if you don't agree with it, I have to take it away.

When Luo Yu saw it, he was anxious. He now deeply understands how precious Shen Yiyi's formula is that he deduced casually. As for the formulas that he got back from Shen Yiyi last time, his grandfather hid them in his own big book that recorded some important information as if he had obtained a treasure, and he easily didn't let others see it. This time, Shen Yiyi deformed the new formulas that he made, needless to say, it must be very valuable. I was thinking about taking it back just now, I thought about it well, and by the way, I invited my grandfather to return the credit, but this time it was taken away by Old Man An, what is it. He was in a hurry, and hurriedly spoke.

"Grandpa An, you can't take this page first. There is also the process of the formula that my classmates gave me one by one. I'll have to take it back and study it. Luo Yu first put forward this reason.

An Zhusheng listened to Luo Yu's words, and smiled: "Okay, Luo Yu, then Grandpa An, I will take another piece of paper today and write you the formula that Shen Yiyi deduced for you." I said that you can't be a kid, you can't catch up with other girls in learning, how can you listen to such a good explanation, but you can't remember it in your heart. You, Grandpa An, and I are so old, I can remember it after listening to it once. Look at it, Grandpa An wrote it to you. ”

As he spoke, An Zhusheng really took out a pen and wrote it down. After a while, he really gave Mo the formula that Shen Yi wrote to Luo Yu at the beginning.

Luo Yu looked at it and said in his heart, do you think I really didn't write it down? I'm also a gifted student anyway, and I have already written it down because I explained it in such detail just now, and I'm just keeping the formula newly written by Shen Yiyi. If I let my grandfather know that Shen Yiyi has a new formula coming out, I can't get it back, and I don't know how to punish me when I go back.

After thinking about it, he actually knew that the old man An Zhusheng had already seen through his little intentions, so he simply said directly: "Grandpa An, my grandfather hasn't seen the formula that classmate Yiyi just pushed to you." You see if I'll copy it for my grandfather first, and then let you take this piece of paper with you. ”

Unexpectedly, An Zhusheng, who had just finished the formula at the beginning of Shen Yi, heard this, it turned out that Xiao Yizhan had never seen the formula he had just gotten, so he immediately put the piece of paper that was still in his hand and quickly put it in the pocket of the close-fitting end of his jacket and put it carefully. What a beauty in his heart at this moment. Ha Luha, old Xiao Tou, it turns out that you also have this day. That day, I heard you say what formula you got, and I wanted to ask you to come and see it, but your little sloppy eyes refused to give it to me, and you couldn't see it. At that time, I said in my heart that it might not be an important formula, so I won't fight with you. I didn't expect that from the formula written by Shen Yiyi, a little girl, today, it turned out to be such an important formula. You old guy is hiding from me, it's really unjust. This time I also have a formula that you haven't seen before, this time I'll let you taste my taste and let you regret it.

thought so in his heart, but of course he couldn't say this to other people's grandsons, otherwise wouldn't he lose his identity as an old man. So An Zhusheng still looked so kind, and said to Luo Yu: "Xiaoyu, it's okay, you just say that this formula Grandpa An said, it is not important to the design of the aircraft, it is for the engine, so you have to let Grandpa An test the correctness of the formula first." Okay, I still have a few things to do, so I'll go first. You two study hard. ”

After saying that, he was afraid that Luo Yu would come to grab the formula, so Old Man An took the first step, patted his ass, and said goodbye. Luo Yu was left dumbfounded. (To be continued......)

PS: What's that, it's still the second watch today.

As for the promised three watches, they will be made up one day.

I watched the Malaysia Airlines report for a day today and prayed for them. Hopefully, they've just traveled to another plane.