Siheyuan: I eat melons while doing scientific research

Chapter 1286 Gao Zhendong's True Colors Revealed (4k, 5k more to come)

"If these two training exercises are completed, our air defense at sea will be basically guaranteed. Even if the air force can't get here in time, it can at least hold the line for a while." Although the joint command center on the island is not very clear about the air defense capabilities of these two ships, they look impressive with their rows of missiles.

"Hey, isn't it strange? The anti-aircraft missiles on the frigate are actually bigger than those on the destroyer. I don't know what the designers were thinking."

The modified "hanging-up" vertical launch system in the mid-to-aft section of the destroyer's hull is covered by a metal plate, so it's impossible to tell what it is from the side. All that's visible is the 8-cell portable anti-aircraft missile launcher in the B gun position, which is naturally smaller than the Haijingqi-62 infrared air-to-air missile modified on the frigate.

These two ships are the mainstays of the South China Sea Fleet, so it's normal that Jiuxing Island was unaware of this.

"I don't know then. Don't worry, the comrades who can build such advanced weapons must be much smarter than us in this regard. There must be a reason for this arrangement." Another comrade was quite open-minded.

"That's right, maybe it's for long-distance shipping, this way there's more space, it's too tough on the ship."

He was half right. Apart from the wall-mounted launcher, the middle section had indeed been modified for airworthiness. After being redesigned and reconfigured, it did significantly improve the passenger space.

While they were exchanging ideas, far away in Beijing, naval comrades also made up their minds.

"Send one destroyer and one frigate from the Eastern Fleet that have completed their conversion training to the south. If anything happens, they will be there to reinforce the Southern Fleet. If nothing happens, consider it the last subject of the conversion training—long-distance voyage training."

"Yes, that's a good idea. There's not much pressure in the strait, so it would be good to move these two ships over there for a while. Comrade Gao Zhendong's assessment that 'there are no large ships in the strait' back then seems to have been very accurate."

At this point, the naval comrades were full of admiration for Gao Zhendong's predictions about the development of technology and application trends at the time. He was a typical example of someone who understood both technology and combat; his predictions were incredibly accurate.

More importantly, the opposing naval and air forces have been severely compressed and forced to retreat. It is now common for our ships to pass directly through the strait, and there are no problems with troop deployment.

"Let's do it! Now I'm actually hoping the Citibanks will do something up there, hahaha."

This is what it means to have a gun in your hand and not panic in your heart.
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Gao Zhendong was unaware that his statement "there are no large ships in the strait" was being praised so highly by his comrades. He was currently receiving comrades from the Southwest Aircraft Research Institute in Fuzhou.

They have already come up with a preliminary plan for an air superiority fighter, and now they are coming to Gao Zhendong to solicit his opinion.

This document contains a lot of information. Transmitting it via current telephone lines and modems with limited bandwidth, without considering security and confidentiality issues, is much slower than simply bringing the design documents over for communication. After all, for the colleagues at the Southwest Institute, hitchhiking is not a problem at all.

As we all know, decades from now, the highest bandwidth transmission method will be trucks carrying hard drives.

Moreover, many things are easier to discuss face-to-face. If you need to draw a diagram on a blackboard, you can't do that over the phone.

"Chief Engineer Gao, this is our current overall plan. What do you think? Do you have any comments?"

Gao Zhendong flipped through the design documents in his hand. It was obvious that his comrades had put a lot of effort into this, and it was basically consistent with the decision made at the meeting at that time, but much more detailed, and all the technologies that could be used were employed.

This thing looks familiar. Gao Zhendong couldn't help but recall what the old man had said: "It's the Tenth Modification."

At first glance, the design in his hand really resembled the twin-engine modification of the MiG-10, or more precisely, it resembled the true swan song of the MiG Design Bureau—the MiG-1.44, only smaller overall.

After all, if the 10th engine is really going to be converted to a twin-engine configuration while retaining the under-fuselage air intake, then the air intake section will likely be very similar to the 1.44 engine, with a design that is quite similar.

The overall configuration that the MiG Design Bureau was still using at the end of the 20th century must have something special about it.

However, in other aspects, it differs greatly from the 1.44, such as the wing sweep angle and the position of the canards, etc.

Looking at the drawing, Gao Zhendong suddenly said, "Change this part."

The colleagues from the Southwest Institute looked at the spot Gao Zhendong was pointing to—the leading edge of the wing. They were somewhat puzzled. They had already implemented all the necessary design and new technologies for the wing; how could anything else be modified?
"Chief Engineer Gao, what needs to be changed here?"

Gao Zhendong made a hand gesture in the air: "Twist this side a bit..."

His words made his comrades understand a little, but not entirely. How to reverse the situation? Why reverse it?
Seeing that his comrades didn't quite understand, Gao Zhendong knew that his gesture was a bit abstract: "Wait, let me draw it for you."

"Hey, you should have drawn it earlier," the comrades thought to themselves with amusement.

Gao Zhendong stood up and drew a schematic diagram of the leading edge twist of an aircraft wing on the blackboard. This design came from the real Tenth Prince many years later.

After the drawing was finished, the comrades looked at it and felt a bit impressed but didn't quite understand it.

Chief Engineer Gao twisted the wing of the new aircraft. Although the angle and position of the twist have not yet been determined, the wing shape he casually drew seems to have a lot of meaning to it.

Gao Zhendong patted the chalk dust off his hands: "We will test the specific torsion angle and other parameters in the wind tunnel, but this needs to be incorporated into the aerodynamic design."

"Chief Engineer Gao, what is the purpose of this twist?"

Gao Zhendong smiled and said, "I won't go into details here, but I'll reveal a little bit first. I recently calculated that this can optimize aerodynamic distribution, improve high angle-of-attack performance, and also benefit aircraft handling and trim. Moreover, it can handle both high and low speeds, which is somewhat similar to the double delta wing. As for why, you can analyze it yourselves, so that you can have a more solid foundation."

Unlike improvements, since it was a completely new aircraft, Gao Zhendong preferred to only provide plans and suggestions, leaving the rest to his colleagues to deduce and experiment on their own.

The colleagues at the Southwest Institute didn't feel anything was wrong. Director Gao was testing us during the Spring Festival, and he had given us both the questions and answers. All we needed now was the derivation process and the specific details of the answer.

This presents a challenge for our comrades, but it also gives us confidence. That's what makes it so exciting!
In fact, some quick-thinking colleagues have already come up with some ideas, but not all of them. They believe that given more time, they will definitely be able to crack the secret behind Chief Engineer Gao's suggestion.

This was exactly the effect Gao Zhendong wanted: once the secret was cracked, the knowledge would be acquired.

Some of the colleagues from the Southwest Institute copied down the diagram that Gao Zhendong had drawn on the blackboard. Taking this opportunity, the team leader said to Gao Zhendong, "Chief Engineer Gao, we have analyzed it and found a small problem. The high angle of attack performance of this aircraft far exceeds that of the aircraft we have encountered before. Under such circumstances, even if we use twin vertical tails, the control efficiency of the vertical tails is not very good."

When he said this, the team leader from the Southwest Institute seemed a little guilty, since they hadn't actually had much experience with aircraft.

The improved angle-of-attack performance of the aircraft brings new problems, which is a sweet trouble for the colleagues at the Southwest Institute. If the angle-of-attack performance were not good enough, this problem would not even need to be considered.

However, as sweet as it is, there are indeed troubles. We can't just keep adding vertical tails like we do with bombers, can we? It's okay for bombers and transport planes because they are low-speed aircraft, but it's definitely not the case for fighter jets.

Upon hearing this question, Gao Zhendong replied without hesitation: "There are two options. One is complex, difficult, and effective; the other is simple, less effective, but usable. Which one should we choose?"

It's such a blessing to talk to Chief Engineer Gao. He can not only solve problems, but also give you choices, which is a very rare thing in engineering applications.

The colleagues from the Southwest Institute laughed: "Chief Engineer Gao, please don't joke with me. You know, of course we want to hear about all of them. As for which one to choose, we'll talk about that later."

Gao Zhendong also realized that he had asked a pointless question and laughed: "The former is similar to a canard, with a fully movable vertical tail, but compared to a fully movable canard and a fully movable horizontal tail, a fully movable vertical tail is much more complicated and difficult."

With the entire vertical stabilizer in motion, the control efficiency is naturally greatly improved, but this is also extremely difficult to achieve.

The canard has better symmetry and less mutual airflow interference, which reduces the requirements for aerodynamics and flight control. In addition, the canard is smaller and the force that the turning point has to bear is less, so it is naturally simpler than the vertical tail overall.

The all-moving horizontal stabilizer is similar; it's even simpler than the all-moving canard because there's no need to consider its impact on the rear fuselage, as it's located at the very back.

However, the all-moving vertical tail brings together almost all the problems. In fact, there are very few companies in the world that have actually used all-moving vertical tails on high-maneuverability, high-speed fighter jets.

To put it bluntly, if the pilot's skills are not up to par, a slight maneuver after the plane takes off can cause a gust of wind to blow the vertical stabilizer off.

The colleagues at the Southwest Institute were also aware that this was not something they could handle right now: "This is a bit too advanced; we'll probably have to wait and see. What about the other one?"

Gao Zhendong laughed: "That's simple. Just make the sweep angle of the trailing edge of the vertical tail smaller. If that doesn't work, vertical or even forward sweep is also an option."

Gao Zhendong didn't even need to draw any diagrams; the comrades at the Southwest Institute figured it out on their own. Some were both amused and exasperated, because when Chief Engineer Gao "fooled things up," he really did.

But what's admirable about him is that this "deception" is truly effective.

It's not that the comrades can't think of it, but the main problem is that people's understanding of aerodynamics is still insufficient these days. It's been somewhat mythologized, so they don't dare to put it into practice. Gao Zhendong believes that this will gradually improve.

"Ah...we've overcomplicated things." The colleague from the Southwest Institute said somewhat embarrassedly.

Gao Zhendong shook his head: "There's no need to be so embarrassed. A small sweep angle or even a forward sweep at the trailing edge of the vertical tail is not without its problems, and it may even bring more disadvantages than advantages. So you need to find a balance. Your idea of ​​seeking stability is not wrong, but our current calculation conditions and wind tunnel test conditions are still acceptable, so we can be a little less conservative."

After speaking, Gao Zhendong pointed to the front view and various sections of the aircraft and said to his comrades, "In this part, don't use a vertical transition. Make it an inverted trapezoid with a slight angle."

The place he was pointing to was the lower fuselage of the aircraft. Because of the twin engines and air intakes, the lower fuselage has a square cross-section, especially the part where the fuselage and the front half of the wing meet.

The two engines of this aircraft are arranged close together, unlike the later Su-27 and MiG-29 of the White Bear, which were arranged with a wide spacing. There is no long recess under the fuselage.

The comrades were taken aback: "Chief Engineer Gao, wouldn't that increase the cross-sectional area of ​​the fuselage's front and increase drag?"

Gao Zhendong nodded: "That's right, it will increase the cross-sectional area and increase the drag a little. However, this way, the internal space will be larger, and more fuel and equipment can be carried. The internal layout of the fuselage will also be more relaxed. Moreover, although the drag will increase, it will not increase by too much. Overall, the advantages outweigh the disadvantages."

"Won't it increase too much?" That's a bit hard to imagine.

Gao Zhendong nodded: "That's right. Although this shape increases the cross-sectional area, you have to consider that the entire aircraft is a three-dimensional geometric body. This shape will reduce the aircraft's wetted surface area in the air. All of this is offset by the shape, so it is actually acceptable overall. Moreover, this shape can increase the lift of the aircraft. You can also consider the aircraft as a lift component."

A lifting body for the fuselage? That's yet another new idea.

Chief Engineer Gao always manages to come up with these fancy tricks. What seems like a small change will turn out to be more complicated than it appears.

"The distance between the two engines can be widened slightly; it's too tight right now. As for the entire fuselage of this aircraft, apart from what's necessary, I hope that the fuselage will have as few protrusions, grooves, and right angles as possible. The entire fuselage should be as smooth as possible, but not round, especially the front and lower half."

Gao Zhendong's true intentions were revealed.

He wasn't thinking about developing a stealth fighter right now—that would be too ambitious. But he hoped to at least achieve one thing: that the aircraft could be easily converted into a semi-stealth aircraft if necessary. Even if it was laying the foundation for future generations, at least it could be quickly modified into a respectable prototype.

"Chief Engineer Gao, the reason for doing this is..."

"Yeah, it's smoother with less resistance, and it looks better too," he said casually.

As Gao Zhendong spoke, he drew the landing gear door on the aircraft schematic as a sawtooth shape and instructed, "If there are maintenance access ports or doors on the aircraft fuselage, do similar treatment; if they are too small, make them hexagonal."

(End of this chapter)