"Xiao Chang, Xiao ...... before. Professor Liu told me that your understanding of this design was very deep and clear when you defended, and to be honest, I didn't believe it a little, but now I can see it. ”

Du Yishan happily picked up Chang Haonan's design plan on the table: "It's really the back waves of the Yangtze River pushing the front waves, my old bones, I am about to lose track of your young people's thinking." ”

"Academician Du praised it, I just used some simulation methods to make an improved model design, and there are still many things to learn from seniors like you."

Chang Haonan is not a random compliment, in fact, Du Yishan has been in the aviation industry since the new century, and has played a very important role in the research and development of a certain type of transport aircraft.

"Heh, that's nice to say." Du Yishan has obviously read this design report many times, and turned to the content of the performance test: "What do you think is the biggest advantage of the mandibular air intake you designed?" Or is there anything else that can be used other than on this plane? ”

This question shocked Chang Haonan's heart, and secretly sighed that Academician Du's vision was indeed good, and he only spent two or three hours at most looking at the design instructions, and found the greater potential of this design.

"In fact, we have found in the simulation that the new air intake channel has more obvious advantages than the traditional design at higher speeds, although the maximum speed of the improved J-7 can only reach Mach 2.0, but we still made some calculations on the flow field distribution and performance at higher speeds. The results show that the inlet design can maintain a total pressure recovery coefficient of more than 0.73 at speeds up to Mach 3.5-4.0 and an incoming angle of attack of 6°, and the performance can be even higher if the design point selection is specifically optimized for high speeds. ”

"Can you get to Mach 4?"

Du Yishan had made a qualitative judgment based on experience, but his eyes were not a wind tunnel after all, and there was still no way to see the specific data.

"Hmm...... We have calculated up to Mach 4, and at higher speeds, the current way of computing and simulation is not very suitable, and we need to improve the method, and we need better equipment. ”

In other words, Chang Haonan means that this design still has potential to be tapped, but it cannot be tapped due to the current conditions.

"As for the use, I think in the short term, we can consider combining it with a liquid-fueled sub-combustion ramjet engine for missiles with a speed of Mach 3-4, and in the long run, if we need to develop a sparkramjet engine and a breathing hypersonic vehicle that flies at more than 5 times the speed of sound in the future, this design idea should also come in handy as a preliminary research."

This time, Du Yishan's eyes were already a little shocked.

In 1996, Huaxia had not even fully built a subsonic cruise missile using a turbojet engine.

In this case, this junior undergraduate student has already begun to think about technical preparation for supersonic cruise missiles, and even hypersonic cruise missiles.

Although it is not that no one is engaged in pre-research in this area, those are basically still in feasibility analysis or theoretical research.

And this inlet design, and more importantly, this integrated design idea, can even be counted as part of engineering practice.

It's a pity that with the current strength of China's aviation industry, there is no way to carry out more in-depth system development work.

Looking at the expression of Academician Du Yishan in front of him, Chang Haonan knew that he should be stable.

Sure enough, after about a minute of ideological struggle, Du Yishan put the design description in his hand back on the table next to him, raised his head and asked Chang Haonan:

"Xiao Chang, I don't know what your plans for your future are?"

Not far away, Professor Liu Hongbo closed his eyes in agony—his last glimmer of hope was dashed.

As a student of Du Yishan, he knew very well that this sentence just now was a standard question before the academician was ready to recruit disciples.

Faced with this problem, Chang Haonan almost didn't think about it: "Since I chose the aircraft department of Beijing Airlines, I naturally continue my studies and use scientific research achievements to help the development of our country's aviation industry!" ”

He had already come this path in his previous life without a system, and it was impossible to change his mind now.

"Hmm...... It's no problem for you to change this course design a little bit as a graduation project, and I can be your mentor for your graduation project. Du Yishan nodded: "As for the future, I have two suggestions here, I don't know if you are interested in listening to them?" ”

Although this is a question sentence, if someone really answers that they are not interested, I am afraid it would be stupid.

"Of course there is, Academician Du, please speak."

Chang Haonan took a deep breath and tried to calm his excitement.

"One, I can make an exception for you to apply for a place to study abroad on public assignment, it may be the United Kingdom or the United States, if you are willing to take this path, then in the senior year, concentrate on overcoming the language barrier, so that you can adapt to the environment as soon as possible after the past."

Du Yishan's proposal was only halfway through, and Liu Hongbo on the other side wanted to get up, looking like he wanted to say something.

Although it is necessary to return to China to work according to the regulations, in this era, there are quite a lot of people who never return after going out, and most of them actually did not have the intention of defaulting at the beginning, but finally chose to stay outside after seeing better living, working and even scientific research conditions after going abroad.

Although public students who refuse to return to their home countries need to repay all the state-funded expenses according to the agreement, and pay an additional 30% of the liquidated damages, given the current income gap between China and abroad, this money is nothing to those who stay in Europe and the United States to work.

Therefore, Liu Hongbo's philosophy has always been that if the student himself has the idea of going abroad, he will not object, but if the student does not have the will to do so, he will not take the initiative to mention it.

He was so afraid that the good seedlings he had taken a fancy would never return.

Especially Chang Haonan, who can be said to be a genius like one in a million, if he really goes abroad, he must also be the target of the other country's struggle, even if he wants to come back, I am afraid it may not be so easy.

"Second, it is also an exception, you can choose to go to my research group and go directly to the doctoral program beyond the master's level. Compared with going abroad, you can get in touch with more practical projects with me, but the conditions are really not comparable with others, and it will be more difficult. If you choose this, I'll get you involved in some key projects as early as possible. ”

"Of course, if you have other ideas of your own, I will try to help, in short, the choice is yours."

"I'll pick the second one." Chang Haonan looked at Du Yishan's eyes and replied.

This was originally his original idea, to prove his ability through course design to participate in specific projects as soon as possible, but the actual situation was smoother than he had expected.

"Really not going abroad?" Du Yishan smiled and asked again: "If you go abroad for further study, you can also build the country when you come back." ”

In fact, if Chang Haonan did not have this system, he might really choose to go abroad, after all, in this era, no matter which one of the United Kingdom, the United States, France and Russia, is much ahead of China in aviation, as long as he learns a little after going out, he will have valuable experience and knowledge after returning to China.

But with the help of the system, the gap in this area no longer exists for Chang Haonan, if he goes abroad, he will contribute knowledge to others, not learn knowledge.

This is contrary to his original intention.