In addition to the changes in the shape of the outer edge of the wing and vertical tail seen in Ding Gaoheng's office, as well as a set of additional fuel tanks on the back, the design scheme placed in front of Chang Haonan also modified the shape of the side strip wing, extending directly from the root of the leading edge of the wing to the side of the cockpit cover.

Because the length is too exaggerated, it will even cause the pilot to get a little stuck when getting on and off the plane, so Guihang's plan also stuffs a small folding boarding ladder under the side strip......

"It's quite thoughtful......"

It doesn't really matter whether there is a land-based aircraft or not, but if you want to get on a ship in the future, it is still necessary.

After all, every inch of land on the deck of the aircraft carrier is expensive and the number of ground crews is limited, and the bits and pieces around the aircraft can be less than the same.

Of course, the designers of the Huaxia aircraft in 1997 certainly did not design according to the standards of carrier-based aircraft, so it was probably just to make use of the ineffective space under the wings.

Chang Haonan didn't even need to calculate such an improvement method, he knew that it must be to specifically enhance the aircraft's maneuverability within a specific angle of attack.

After such modifications, the whole aircraft suddenly looked at it, and it felt a bit like a single-tailed and single-engine F18.

"After returning from Rongcheng last time, we followed your ideas and carried out a complete overhaul of Jianjiao 7, and the current aerodynamic design of the first version has been basically completed."

Seeing that Chang Haonan had opened the project documents, Sun Huizhong hurriedly came to the side, and took out a stack of photos from his pocket while introducing the results of the recent period of work:

"The current problem, one is that I really don't know how to design the DSI intake, so I first used an ordinary D-shaped partition inlet instead, and the other is limited by conditional factors, there is no way to do structural calculations, so for the time being, I only made a wooden model and filled in the internal equipment to see."

Chang Haonan took the photo and took a few brief looks.

It's kind of a novelty.

In the previous life, when he entered the aviation industry and finally came into contact with aircraft design after all the way through the struggle, even the Beijing Olympics were about to start, so naturally he had not been exposed to this traditional craft.

"It's not me who said, Sun Gong, this model of yours is quite good, and I feel that it can be used as a handicraft."

"Alas...... It is a shame to say that over the years, the best business of our Guihang development is wooden furniture, and it has even been exported to several Middle Eastern countries. ”

Speaking of this, Sun Huizhong, as an aircraft designer, is always a little embarrassed-

Aircraft manufacturing companies, which have never even exported airplanes, but export furniture.

However, this is nothing in the eyes of Chang Haonan, who has returned from more than 20 years later.

Well, if you have a side hustle, of course, you can do a little if you have the conditions.

Chang Haonan didn't dwell too long on the issue of internal structure.

As far as a simple light training aircraft is concerned, it is not required to have particularly exaggerated structural strength, and the optimization focus is mainly to reduce the weight as much as possible, which can be handed over to Guihang for training.

"I see that you have made some changes in the design of the edge wing to improve the reduction of the linearity of the lift curve at medium and medium angles of attack?"

Hearing this question, Lin Tongxin, who had been staying behind Sun Huizhong just now, lit up:

"Director Chang, you ...... See? ”

In fact, in terms of age, Lin Tongxin, who graduated with a doctorate, is several years older than Chang Haonan, but after this period of experience, the latter can no longer see too many traces of being an undergraduate graduate in his early twenties.

"This design was proposed by Kobayashi after he joined the company, and after the modification, we simply calculated it ourselves, and it is indeed good for improving the handling."

Sun Huizhong immediately explained.

"Of course, the small size of the side strip wing, or similar structure of the edge strip wing, is the main reason for the slope drop of the lift curve at small and medium angles of attack, and this strong and irregular nonlinearity is very difficult to control for early mechanical or analog fly-by-wire flight controllers."

Chang Haonan put the photo in his hand aside, picked up the mouse again, and enlarged the part of the strip on the screen:

"Both the Su-27 and the F15 suffered in the early days of design in this regard, and I think you probably found some inspiration in the F18."

"This ...... You've got it all right. ”

Lin Tongxin's whole person instantly became excited:

"This is the conclusion that my supervisor told us when I was studying for a master's degree and did a project, and I didn't pay much attention to it at the time, but I encountered a similar situation as soon as I joined the company this year......"

The other party's reaction made Chang Haonan smile, recalling that when he had just graduated from the aviation industry in his previous life, he seemed to be in a similar state to him......

Then he was quickly educated by reality.

There is still a difference between the actual work and the things learned in school.

In fact, many of the early third-generation designers with edge strips faced the problem just mentioned, which was that the aircraft could maintain some maneuverability at large angles of attack, but were prone to loss of control at medium angles of attack.

That is, the moment characteristics are very poor.

A lot of weird-looking designs are designed to solve this problem.

It's just that the level of aerodynamics has developed far beyond what was originally expected, and by the mid-to-late 90s, there were already a lot of ingenious designs to improve the linearity of the torque, and combined with the huge advances in flight control technology, the problem was practically non-existent.

Thinking of this, he decided to say a few more words:

"The knowledge is indeed very solid, but I still need to put some effort into learning and applying."

Lin Tongxin, who just thought that his thinking was completely guessed and was recognized, suddenly froze:

"Ah......h

"When I was studying for a master's degree, it should still be in the early 90s, and the situation is still a little different from now, in fact, in terms of the response speed and control ability of today's fly-by-wire flight controller, as long as the design level is appropriate, there will be no problems in this regard."

Speaking of this, Chang Haonan pointed to the part of the plane hanging down on the computer screen and said:

"On the contrary, the edge strip you designed in this way may induce a divergent oscillation in the tail part, which is a test of the strength of the vertical tail root, if you look closely, you will find that the F18 vertical tail root is designed with three sets of stiffeners, which is to deal with this problem."

"This ......"

Lin Tongxin felt relatively good about himself just now, and when he was said this, he suddenly felt a little embarrassed, so he had to scratch his head in embarrassment.

Of course, Chang Haonan also knows that at this time, he can't blindly hit other people's self-confidence, so he changed the conversation:

"However, you can have this kind of thinking, and not just mechanically carry out the instructions of the leader, which is more than many people."

The reason why I say this is by no means Chang Haonan in Versailles.

The kind of peerless genius who can change the world by himself is very rare after all.

Take himself as an example, without the help of the system, he would certainly be able to achieve some remarkable results by relying on the experience and technology of his previous life, but it is absolutely impossible to get to this point.

The path of career development for the vast majority of people is gradual.

The key is to have the opportunity, the resources and the courage to try.

Therefore, although this Lin Tongxin may not be very strong spiritually, he is definitely a malleable talent.

Not to mention anything else, how many people can still remember a casual sentence from their supervisor during the master's degree program after graduating from their PhD?

But he remembered.

"If you're interested, I just have a simpler solution here that can build on the original design and further improve the available angle of attack."

Chang Haonan said as he pulled a piece of coordinate paper from the side and drew a picture on it:

"Designing a retractable small-sized edge strip on the side of the nose can reduce the unsteady lateral force and yaw moment generated by the asymmetric vortex of the nose at a high angle of attack, and at the same time, it can also use the lateral force generated by the edge strip vortex to generate a moment that hinders yaw, and because the size of the nose edge strip is almost negligible compared with the wing and flat tail, it will not affect the longitudinal aerodynamic balance that you have done."

"However, the telescopic structure takes up a considerable part of the nose space, so it is really a bit of a chicken for fighters that pursue the size of the radar antenna, and I have not applied this design to a specific model."

He handed the drawn schematic diagram to Lin Tongxin next to him:

"If you want, you can take advantage of this time in the capital to try this new type of training aircraft to see if you can build a special high-angle of attack and high-mobility technology verification aircraft."

"On the one hand, the trainer has certain requirements for the controllability of the super large angle of attack, and the cost of this program is very low compared to other means, and it can be used, on the other hand, it can also be regarded as an opportunity for your Guihang to show its face, selling aircraft This kind of thing, sometimes it is similar to selling other things, you have to make some gimmicks to be paid attention to......"

Having said that, how could the latter have a reason to refuse, and immediately took the coordinate paper with both hands:

"Of course I do, thank you Director Chang for the ideas and opportunities!"

The writer's assistant made a new green content plan, and when I posted the previous chapter, I clicked in and tried it, but it directly deleted the next paragraph of my content...... The last chapter was almost less than 2,000 words......

(End of chapter)