Just then, the door to the classroom was pushed open, and four more people walked in from the outside.

This school building is shared by their entire School of Aeronautical Science and Engineering, so it is not surprising that there are other students in the classroom, and if it is before the end of the semester, there may even be twenty or thirty people in one classroom at the same time, so the four people who are concentrating on the plan do not care at all.

"Haonan?" One of the four people who just came in was Chang Haonan's upper bunk Huang Zhiqiang, and he naturally recognized the former at a glance: "You are also doing curriculum design here?" ”

In fact, Huang Zhiqiang specially found here.

Since the beginning of the semester in March this year, Chang Haonan has always looked bitter and hateful, and almost everyone in the dormitory knows about designing a fighter jet.

It's just that for Huang Zhiqiang, Chang Haonan in that state is not worth worrying about, he knows very well where the upper limit of the other party is, and people's abilities will not be improved because of anger.

And he didn't think there was anything to be angry about.

However, this morning, Chang Haonan's unusually lightweight appearance made him feel a little uneasy, so he decided to "scout" to see how far the former had achieved.

"Yes, Lao Liu's class, it's not sloppy......" Chang Haonan didn't look up, but continued to draw sketches of the air intake and nose part on the paper, ready to tell the other three people what they needed to do.

In addition to the 10 credits of aircraft design, which is second only to the graduation project, which will greatly affect the grade point average, Liu Hongbo will also invite many bigwigs in the college as judges in the defense of the final course design.

And these people are often the judges when the admission interview for exempted graduate students is conducted.

The interval between the two events is usually only about a month.

Therefore, all students who are interested in further study must devote 12 points of energy to this subject.

The four people who had just come in put the tools and books they were carrying on a table not far away, and then Huang Zhiqiang, who was the leader, slowly walked over towards Chang Haonan: "Anyway, where have you go?" ”

"I've just chosen a design plan, so it's early."

Chang Haonan still didn't look up.

He really didn't have much impression of Huang Zhiqiang, and he didn't take the other party too seriously at all.

The next thing to say is just a precursor to the design work, so I don't care about being heard.

And whether you can understand it or not!

However, Zhang Man was very vigilant about Huang Zhiqiang, who was constantly approaching, and directly took a step to the side quietly, blocking the latter a few steps away from the table.

Huang Zhiqiang tried several times, but because the aisle between the tables and chairs was really narrow, he still couldn't get past the barrier.

"Cut ......"

Although there was no way to take a step further, the petite Zhang Man could not block his vision, Huang Zhiqiang easily saw the two black and white photos on the table, and the sketch that Chang Haonan was hand-drawing, so he took it for granted that this was to be reproduced through the photos.

This immediately reassured him, shook his head and turned to leave.

"Big waste can only teach small waste, and in the end you have to copy it according to the Soviets, and besides, the design of the aircraft is not a sketch, what can you design in front of two photos?"

Huang Zhiqiang thought to himself, and sighed that he was a little too worried just now.

At this time, Chang Haonan didn't know that he had been scolded in the hearts of others, he had already finished drawing two schematic diagrams, and took a piece of paper to prepare to list the steps on it.

The other three people also hurriedly took out their notebooks and pens to prepare for the record.

They still remember yesterday that the senior sister who was in the second year of the doctorate and whose tutor was the academician himself took notes obediently in front of Chang Haonan.

"The process is like this, because we are designing the air intake tract and the front fuselage as an integrated design, so I will first select five different design initial values, which are the cone precursor, or the half cone angle of the radome." Chang Haonan pointed to the tip of the radome on the sketch and marked a α symbol on it: "What the three of you have to do is to help me determine the design parameters corresponding to each initial value." ”

After more than 20 years, this process can be completely done by a computer, but at this time, at least under their current conditions, a lot of things still have to be calculated, especially the relevant engineering manuals.

Zhou Shuwan and the three of them nodded like chickens pecking rice.

"The steps are like this, I'll say it first, if you don't understand something, you must ask to understand."

Chang Haonan said and wrote a (1) on a piece of paper.

"The first step is to set the tapered precursor busbar, fix the initialization half cone angle and make it dimensionless according to the tapered length."

"The second step is to do it, and use the average flow field Mach number in the area near the entrance of the inlet as the benchmark flow field design to flow the Mach number, because this is still an aircraft after all, so the design point behind it should be about Mach 1.6, which is not too high."

"In the third step, the intersection point of the three-dimensional inner transformation line of the inlet in the longitudinal symmetry plane of the conic precursor and the bus bar of the conic precursor is taken as the installation positioning point, and the angle between the axis of the incident inner cone shock wave of the inlet tract and the axis of the cone precursor is calculated as the installation angle of the inlet tract, and the specific calculation method is ......"

"In the fourth step, the shape of the upper lip of the inlet tract is obtained by the intersection of the incident inner cone shock wave of the inlet tract and the lower plane of the cone precursor, and the shape of the medial lip is obtained by the intersection of the incident inner cone shock wave of the inlet tract and the longitudinal symmetry of the conic precursor......"

"The fifth step is also done by me, based on the three-dimensional shape of the inlet inlet, and the internal surface of the inlet is generated by streamlining in the selected reference flow field......

"According to these five steps to calculate the air intake, theoretically is the optimal design under the selection of half cone angle, as for which of these designs is better after being installed on the fuselage of the MiG-21, you need to do CFD simulation like yesterday, when I run the results out, you are responsible for sorting out the data and making charts, you should be able to intuitively find out the optimal solution."

Of course, among the steps given by the system, there was a process of going to the wind blowing tunnel at the end, which was directly ignored by Chang Haonan.

If he can directly apply for the resource of supersonic wind tunnel, he will still use it to change the J-7 with three undergraduates?

After Chang Haonan wrote down the last step on the paper, he threw the pen aside, stood up and looked at the three teammates in front of him: "Do you understand?" ”

There was silence......

"Hmm...... I understood some of them, but I wasn't sure what I didn't understand. Zhou Shuwan scratched his head with a distressed expression: "Let's go to the library first, and then we will start calculating first, and if we can't calculate it, we will ask you again." ”

"Okay." Chang Haonan nodded, and then packed his own things on the table into his bag, while Zhou Shuwan almost habitually helped Zhang Man sort out the large pile of materials she brought, and the group of four quickly got up and left.

The area of this classroom is not large, and Chang Haonan did not deliberately lower his voice when he spoke just now, so the four Huang Zhiqiang sitting next to him also heard these contents clearly.

"Brother Qiang, did you hear what Chang Haonan and the others discussed just now?" One of them approached Huang Zhiqiang and whispered, "What do you mean, they seem to have ideas like this?" ”

Huang Zhiqiang frowned when he asked a question, and glanced at his teammates next to him with some unhappiness.

He didn't understand either!