Chang Haonan didn't delay for too long, and after Liu Hongbo turned back to maintain order, he began his explanation:

"In view of the shortcomings of the J-7, the main fighter of the People's Air Force, which has poor all-weather combat capability and does not have over-the-horizon combat capability, our group changed the nose air intake of the original model to a mandibular air intake, and the left nose space can be installed with a radar with a diameter of no more than 560mm, and at the same time, the flight performance of the aircraft is equal to or better than that of the prototype."

"In addition, with the rapid development of supersonic vehicles, the boundaries of separating the aircraft from the power plant, inflow and outflow have been broken, so in the design process, we have adopted the integrated design scheme of the mandibular inlet / cone precursor, which has been verified by computer simulation, showing that the air inlet / cone precursor / engine is well matched, which reflects the advantages brought by the integrated design, and the design ideas are now explained as follows, and the calculation process is located on pages 14-15 of the design description, Fortran programming and Fluent software were used in the calculation process......"

"The performance analysis of the integrated model of air intake/cone precursor is completely carried out by computer, and the simulation ideas and simulation methods are as follows......"

"In order to test the reliability of the calculation method used, this paper uses the biellipsoid model with detailed performance data on pages 213-217 of the textbook for numerical verification, and the results are shown in the figure."

"The results obtained in this paper are in good agreement with the experimental data under different incoming Mach numbers and different incoming angles of attack, which indicates that the reliability of the calculation method used in this paper is ......"

At first, the judges just listened, but soon, they realized that the design was very complete and the idea was perfect, and it was by no means a semi-finished product, so they began to flip through the design instructions in front of them, and discussed a few words in a low voice from time to time.

And when Chang Haonan began to talk about the specific design process, the four of them even opened the book and began to quickly record it on it.

Of course, the four professors are all involved in CFD simulation, so they don't have to copy everything Chang Haonan said like Yao Mengna, they just need to write down some interesting ideas.

But for the rest of the students in the back of the room, the scene was already shocking.

On the stage, an undergraduate student was talking endlessly.

Offstage, the four judges were actually ...... Taking notes?

As for the specific content of what Chang Haonan said, not too many people care about it.

I don't understand it anyway.

Huang Zhiqiang, who was still full of confidence in himself just now, was even more stunned when he saw this scene - obviously the reason why the design instructions were only half the thickness of their group was because there were a large number of steps that were not there, or did not need to be reflected on paper.

As for the three-dimensional shape design of the inlet entrance that he said in the design manual in his hand, which "needs to rely on experience" to complete, Chang Haonan directly showed a beautifully drawn half-model schematic diagram, and made several judges nod their heads again and again in two sentences.

Just because he doesn't understand doesn't mean that the teachers can't understand, Chang Haonan's thinking is obviously recognized.

"After the design was completed, we compared the aerodynamics before and after the improvement, and the total pressure recovery coefficient of the inlet tract was above 0.950 at a speed of Mach 1.5, an angle of attack of 0 to +10° or a sideslip angle of 0 to 6°."

"With a speed of Mach 0.8, the total pressure recovery coefficient in the same angle of attack or sideslip angle is above 0.968, and the total pressure distortion index is not more than 0.14 in the range of flow coefficients matched to the engine."

"The new inlet design offers a performance improvement of about 3 to 8 percent at subsonic speeds compared to the original design, and more than 10 percent performance improvement between 1 and 2 times the speed of sound."

"Compared with the MiG-21MF intake design, which enlarges the air intake head cone and installs a radar, the performance in the full speed range is at least 23% higher, and the cone-shaped front body can accommodate a radar with a maximum caliber of 560mm, which is enough to lock on to a target the size of a fighter at a distance of about 30-40 kilometers according to the current model."

Although the previous content is obscure, the data indicators mentioned by Chang Haonan at the end can still be understood by the students here.

As a result, the back of the classroom, which had been silent just now, quickly boiled over again.

In the mid-90s, over-the-horizon combat was the most urgent issue to be solved by the Air Force, and it can be said that the difference between 0 and 1 was whether or not there was over-the-horizon combat capability.

It is also because of this that for a long time, the "pointed aircraft" that could be equipped with a large-caliber radar were synonymous with advancement, and only a small number of J-8B and Su-27 had such characteristics.

And today, they actually saw an improved J-7 that also has this characteristic and can be equipped with radar!

Don't look at the number of 30-40 kilometers seems not to be big, you must know that the AIM7F air-to-air missile, the main force of the US military in the 90s, the maximum range of a head-on attack is only 40 kilometers, and the Aspide purchased by China from Italy and the Thunderbolt 11 copied on this basis have a range of only 30 kilometers, so this 560mm nose is enough at the moment.

Not to mention that on this basis, the flight performance of the aircraft not only did not decrease, but on the contrary improved!

"If this J-7 improvement is paired with the Thunderbolt 11, it will already be similar to the F16! F16 with AIM7 can also play more than 30 kilometers. "Most people who study aviation still have some understanding of the Air Force

"Well, that is, there may be a certain gap in terms of range, after all, the size of the aircraft is there." The other seemed more sensible, but there was a clear excitement in his tone.

"Hey, what's the problem with a short range, we don't bully others like the Yankees, I think, if we could have 200 at the beginning of the year, no, we could have 100 of this improved J-7, those two aircraft carriers would definitely not dare to be so rampant!"

This sentence instantly won the unanimous approval of the people around him.

Although China's aviation industry is still relatively backward, the J-7 can still be supplied openly, but the current model of the J-7 has been backward after it has been manufactured, so it can only maintain a small amount of production.

For a while, although everyone's opinions were not unanimous, the entire classroom almost began to discuss the aircraft's performance, cost, manufacturing difficulty and even the prospects for equipping the troops.

In fact, not only the students in the back, but even several judges and teachers began to consider, is this improved model really possible to land?

"Xiao Chang, although your design still has some things to be improved, but from my personal point of view, there is nothing to ask, if I am asked to do it, I will definitely not come up with a better plan than this."

Professor Li Guang, the eldest of the four judges, took off his reading glasses and said, looking at Chang Haonan with relief in his eyes: "So I want to ask, do you think there are any problems that need to be solved in the manufacture of this aircraft?" ”

This is almost impossible to have a higher evaluation, you must know that this course only requires aerodynamic design, and manufacturing problems are not included in the scope of assessment.

And Chang Haonan has long been prepared for this.

"Hello Professor Li, we have considered this problem at the beginning of the design, this improved model and the original model have 60% of the parts can be common, and the performance requirements of the new parts generally do not exceed the level of the MiG-21MF, but considering the weight of the radar, in order to maintain aerodynamic balance, some composite materials need to be applied in the air intake tract and radome part to reduce weight, accounting for about 2% of the total material of the fuselage."

The 2% amount of composite materials is not a new thing for the Huaxia aviation industry, and there has been experience in the J-7M, J-8B and J-7 before.

Therefore, this answer is basically equivalent to 'there is no problem that needs to be solved', but it is not humble enough to say so, so I found a problem that is not a problem.

"I think, if you have the conditions, can you build a scale-up model and go to Mianyang to blow the wind tunnel and try it?"

Liu Hongbo's voice was not very loud, and he said it to the other three teachers, but someone still heard it.

The wind tunnel in Mianyang is not a small fight in the school laboratory, and going there to experiment, even if it is just a scale-down model, means that the scheme really has the possibility of taking root.

You know, this is just a junior year course design!

The already silent discussion sounded again, but this time, more people's attention shifted to Chang Haonan.

Obviously, the word Xueba is no longer enough to describe such a person.