On the other side, Chen Nian and Chen Guo rushed to the airport by special car, without saying anything all the way.

In fact, with the level of the two of them, they couldn't arrange a special plane, but there happened to be a plane that was about to go to Chang'an to perform a mission, so the two took a ride.

This flight will last more than four hours, Chen Nian is not willing to waste time, so he took out the aerodynamics notebook that he had prepared long ago on the plane and began to study.

It is said to be learning, but in fact, it has progressed to this point, mainly based on calculation, and the object is also a number of difficult problems left over from Chen Guo's notebook.

Chen Guo, who was sitting on the side, looked at his hand curiously and asked:

"Isn't this my notebook? Have you read it all? ”

"Yes, what you see on the desktop in your study, you can see it, I won't ask for it."

Chen Nian replied with a smile.

"No, my point is, you've read it all? How long has it been? ”

"It's kind of a read, but it's just a preliminary understanding, most of the questions left in your notebook at the end, I don't even have ideas, and those who have ideas don't know what method to use to solve, isn't this researching?"

Hearing his words, Chen Guo nodded slightly.

In fact, this notebook was not left over from his college days, but after graduating with a doctorate and starting to teach, one day he suddenly felt that he had never sorted out the knowledge system, so he started from the most basic textbooks and "learned" the whole aerodynamics.

What remains is this notebook.

Therefore, this notebook does not represent the knowledge level of a genius undergraduate, but the review and collation of a doctoral student.

Naturally, his concerns will not be those of undergraduate level.

Most of the last dozen problems in the notebook were at the forefront of the time, including the high angle of attack circulation, pulsating crosswind problem, hypersonic boundary layer instability measurement method, and so on.

If these problems can be solved at Chen Nian's current level, then there are really ghosts.......

Thinking of this, he opened his mouth and said:

"You don't have to put too much energy into these questions for the time being, because every question I list is actually a complete research topic."

"If you want to solve it, it will take a lot of time and manpower and a lot of experiments to complete."

"You still focus on laying the foundation now, read more exercises in the textbook, and if necessary, I will also find you some other exercises to do."

"When I think your level is enough, I will pull you into the group and study with other graduate students."

Chen Nian nodded, he had already realized this situation, but .......

Not all of these dozen problems must be solved through experiments!

For example, the aerodynamic uncertainty mechanism with a large angle of attack, in fact, when analyzing the F-22 body, sufficient data has been obtained, and now he just lacks a simple way to organize it.

----Or to put it bluntly, he already has the answer, but he doesn't know how to write it.

"Professor Chen, I understand what you said."

"However, when I was looking at your notebook before, I also had some thoughts and wanted to talk to you about them."

"For example, this large angle of attack aerodynamic uncertainty problem, I feel that it actually has a way to solve---- especially when using the slender body as a template for analysis."

"You see, the essence of this problem is actually to solve the problem of asymmetry around the flow caused by slender aircraft----such as missiles and fighters) when performing large-angle maneuvers."

"The difficulty lies in the fact that the orbital and aerodynamic characteristics of the slender body aircraft are too complex in the case of transonic speed and high angle of attack."

"But no matter how complex it is, it can eventually be broken down into a few questions."

"The first, the asymmetrically separated front vortex at angles of attack above 30 degrees; the second, the transverse lateral aerodynamic force that reaches the normal force; Third, the randomness of the prevortex. ”

"These problems lead us to solve the Navier-Stokes equations, the larger the angle of attack, the worse the linearity, and finally it becomes almost random."

"But what if we found a complementary mechanism that could reduce the randomness of the Navier-Stokes equation? Or what if we could reduce the probability of asymmetric eddy fields through some kind of shape design? ”

Chen Nian finished his inference in one breath, in fact, he already knew the answer to this question.

The symmetrical + word layout will induce the generation of asymmetric front vortex fields, amplifying aerodynamic uncertainty, and the best solution to this problem is either a flat front wing layout, similar to a waverider, or an asymmetrical front wing, similar to some surface-to-air missiles that can turn at right angles.

But how to deduce from the problem to the conclusion is a bit beyond his ability.

----However, even if it was just like this, Chen Guo, who was listening on the side, was already so shocked that his eyes were about to pop out.

How could he have thought of using the Navier-Stokes equation to solve the flow around an elongated body?

No, he can clearly explain the basic reason for the uncertainty of high angle of attack aerodynamics?

I didn't write this thing in my notebook!

You must know that I have been specializing in the direction of high angle of attack mechanics in aerodynamics since my graduate studies, and the uncertainty of high angle of attack aerodynamics is the most difficult part of it.

For a long time, there has been no safe solution to this problem in the field of aviation research in China.

What was the solution at that time?

Don't fly big angles of attack!

Or, if you must fly at a high angle of attack and a large angle, you can achieve it by widening the wing surface.

This is clearly a compromise for the sake of stability.

It is only in recent years, when the timing of wind tunnel simulations has increased, and the results of some problem simulations have become more accurate, that there has been a breakthrough in this problem.

And the solution ........

"Do you know how to solve this problem?"

Chen Guo asked.

Chen Nian hesitated for a few seconds and replied:

"I didn't finish the push, but based on the current direction, I can roughly guess the result."

"I think the first thing to solve is the problem of cross-symmetrical airfoils, which can be completely solved by waveriders, or with spiral asymmetrical airfoils---- of course, this is only for missiles."

"For the aircraft, it has to be the F-22's multi-sided strip-assisted lift layout, which we have discussed before, and the vortex on the wing surface will cancel out part of the asymmetric separation of the front vortex."

"Bang!"

The cup in Chen Guo's hand slammed heavily on the small table, and he looked at Chen Nian in disbelief, as if he was looking at a glowing treasure.

After a long time, he asked intermittently:

This conclusion....... Is it you, did you push it out yourself? ”

Chen Nian nodded and took out another notebook from his backpack.

And that notebook is densely packed with his own calculations.

"It's not a push, it can only be said to be a half-push and half-guess, my current foundation is still too weak......."

"Are you still weak?"

Chen Guo's eyes widened.

"Your level is stronger than when I was a sophomore!"