Siheyuan: I eat melons while doing scientific research

Chapter 1386 So This Is the Price (4k)

"Just kidding, you make it sound so simple. Such a big canopy is not easy to integrate."

"It doesn't have to be a single piece. Just divide it into two parts, and the small frame in the middle won't have a big impact."

"That's right. If we apply microwave-absorbing coating to the middle frame, we can eliminate the impact of the frame." The comrades knew a little about microwave-absorbing coating.

"Nonsense, radar-absorbing coatings are much more difficult to make than canopy coatings..." Knowing this is one thing, but figuring out how to make them is another.

Upon hearing this, Gao Zhendong raised his hand and smiled, "You don't need to worry about the paint."

"Oh, I almost forgot there's a big shot in materials science squatting here," the chief engineer of the National Defense Industry Committee chuckled to himself. Although Gao Zhendong is known publicly and semi-publicly for his work on metal materials, who knows if he might actually be quite skilled at these strange and unusual things?

After all, everyone knows that Gao Zhendong spans many fields, making him seem like an octopus.

Gao Zhendong: Ferrite also has the word "ferrite" in its name, so there's nothing wrong with that.

The colleagues at the Southwest Institute exchanged glances, their eyes filled with excitement! What did this mean? It meant that the radar-absorbing coating might be used on more than just that thin canopy frame.

“There are still some problems. Look, even with a two-section design, the canopy area is still quite large, and the thickness is considerable. This places extremely high demands on the ejection linkage system.” This person clearly knew that area very well.

The thickness and sturdiness of an integrated canopy are indeed very large, which can cause many other problems. Therefore, Gao Zhendong knew that our first fourth-generation fighter jet, after initially using a frameless integrated canopy, later added an internal frame – a result of careful consideration. It wasn't that we couldn't do it, but rather that it wasn't necessary. Developing technology can be impressive, but there's no need to sacrifice practical benefits for the sake of showing off; that's just being wasteful.

Gao Zhendong interjected again: "It's not that complicated, just blow open the canopy!"

"Explode?" Not only the comrades from the Southwest Institute, but even those from the Air Force Equipment Bureau were stunned. Was this a rescue or a murder?

Imagine a bomb exploding inside the cockpit; all the comrades felt that this was far too novel.

Gao Zhendong laughed and said, "It really is possible. Pilots have helmets. And it's not a bomb, but a thin detonating cord. It doesn't have to blow the canopy open directly; it just needs to make the structure more vulnerable so that the ejection seat can be pushed open more easily."

The comrades then began to believe that it was indeed possible, if it was just a matter of making the canopy structure a little weaker.

"We will ask the relevant factories and institutes to conduct experiments on this matter; you can just use the finished products. What you need to do is cooperate well and make your requests!" said the chief engineer of the National Defense Industry Committee.

Gao Zhendong never speaks carelessly. Since he said this, it means that he has really considered this matter and that there is a high probability that it will come to fruition.

Seeing that the National Defense Commission had taken on the task, the comrades at the Southwest Institute were completely relieved. Then they focused their attention on the largest opening on the front of the aircraft, which was also the most troublesome part—the air intake!

Looking at this thing, the comrades all felt like they were trying to eat the sky but had no idea where to start.

"Committee Member Gao, this air intake is really troublesome. To be honest, making the air intake the way it is now to ensure the aircraft's aerodynamic and dynamic characteristics has reached our current limit..."

Gao Zhendong looked at the aircraft sketch, which was similar to what he had expected. It was an adjustable air intake similar to the later Polar Bear 1.42. Moreover, like all early ventral air intakes, including the Pitot tube of the American F-16, the J-10 Rogue, and the European Typhoon, a partition was added between the ventral air intake and the air intake.

However, it is precisely this isolation that brings about the biggest problem—signal reflections here are very strong.

This is indeed a difficult area to handle for the colleagues at the Southwest Institute who are not yet very experienced.

"This partition is to address the boundary layer issue, right?" Gao Zhendong asked, pointing to the upper lip of the air intake.

"Yes, this is the simplest way to solve the boundary layer problem. As for the adjustable air intake, it's to solve the problems of air intake efficiency and airflow stability at different speeds." Committee Member Gao, who has produced textbooks on aircraft aerodynamic design, understood this at a glance.

Gao Zhendong laughed and said, "Now you have two options..."

There could be two more?! I don't have a single one here! The comrades at the Southwest Institute were overjoyed.

If their own work is like filling in the blanks, then what Committee Member Gao did was like doing multiple-choice questions, and even had all the correct answers. If only exams were like this when we were in school!

"Committee Member Gao, what are the two options?"

Gao Zhendong pointed to the belly of the fuselage: "First, modify the shape of this partition and the fuselage as much as possible, making it as close to the fuselage as possible, and the distance between them should be basically the same. That is, the belly of the fuselage and the upper lip of the air intake should be basically parallel. At the same time, carefully adjust the shape of the upper lip and the distance between it and the fuselage according to the radar wavelength to be dealt with."

The upper lip is a straight line, which naturally reflects radar signals strongly. Replacing it with an isosceles triangle with a certain angle would be better. Similarly, the gap between the upper lip and the fuselage, if properly spaced, can significantly attenuate radar signals of specific wavelengths.

The Americans aren't stupid either. There's a gap between the F-22's Garrett air intake and the fuselage, but that doesn't prevent its frontal radar cross-section from being kept very small.

As Gao Zhendong spoke and explained, the people from the Southwest Institute listened and nodded.

Although the upper part of the air intake cannot be modified indefinitely, the outer contour of the fuselage can be modified slightly to accommodate the upper edge of the air intake. With a two-way approach, this is indeed possible.

"As for the second method, it's a bit troublesome..." Gao Zhendong pondered, thinking that this might not be the best option for this plan.

"It doesn't matter if it's troublesome, as long as there's a way." Whether it's troublesome or not, it doesn't necessarily have to be used on this plane. The comrades at the Southwest Institute now had a backup plan, which greatly reduced their pressure.

Gao Zhendong nodded. That's true. Anyway, let's get the method out first. As for when it can be used and in which generation, that depends on the progress of our comrades. "In fact, to eliminate the boundary layer and maximize the adaptability to speed, we don't necessarily need this baffle. We can even adapt well to the entire speed range from low speed to 2.5M high speed without any adjustment device."

Going any higher is probably not an option, but Gao Zhendong is still aware of this speed range, since he has seen the actual product before.

The colleagues at the Southwest Institute were completely stunned. Such technology existed? It could adapt to a speed of 2.5M without needing anything?
It would be fine if low-speed fighter jets didn't need anything, but they had never seen a simple way to adapt to such a wide speed range and solve the boundary layer problem without needing anything.

It is said that you can't expect a horse to run fast without feeding it, but Chief Engineer Gao's words clearly mean both, and this kind of wanting both is even more excessive than that of the comrades in the army.

It was all good, even the plane was lighter and simpler, which made the comrades feel that all their previous work had been in vain.
No, that's not quite right. Perhaps Committee Member Gao only recently paved the way for this; he himself didn't even know about it before. That's quite possible, after all, something so far-fetched wouldn't happen without taking some time. Oh, right, even if it took time, that seems unlikely.

"Committee Member Gao, to be honest, we really didn't expect this." The comrades from the Southwest Institute were very honest; this was beyond the limits of their thinking.

Gao Zhendong picked up the chalk and drew a bulge on the blackboard, making some of the younger comrades blush. This thing looked...tsk tsk tsk...

The chief engineer of the National Defense Industry Committee and the comrades of the Air Force Equipment Bureau naturally didn't have this idea. Damn it, we're working on equipment, we should be serious. It's just that this thing looks too simple, so it must not be finished.

Then Gao Zhendong made a few strokes and then threw down the chalk.

The comrades were dumbfounded. So that bulge really was the technical secret you mentioned? Because Gao Zhendong's next few strokes were all about the outline of the fuselage and air intake, and there was nothing unusual about either of them.

Judging from this, the incredible air intake technology he was talking about looks like this—extremely simple.

Looking at his comrades' expressions, Gao Zhendong laughed: "Comrades, you guessed right. This little bulge is the key to solving this problem. It looks simple, right? But this is just a schematic diagram. The most troublesome part is how this bulge should look on different aircraft, how high and how big it should be, and how to determine the curvature of the circle!"

This thing looks really simple, and aside from being a little tricky to manufacture, it's all good. But its downside lies entirely in its design! It looks simple, but it's difficult to make.

Not to mention the super wide air intake of the Twenty, even for something as fast as the Ball Electric 2, there are only two companies in the world that can actually make it: us and the Americans.

"Committee Member Gao, is this really going to work?"

Gao Zhendong was delighted. "I may not be confident about other things, but I can guarantee that this little bag will work!"
"It really works. Okay, let's put aside the specific implementation for now and let me introduce the theoretical aspects to you all..."

"Great! Great!" The actual implementation certainly cannot be achieved overnight, but the comrades at the Southwest Institute were very happy to hear and understand the principles.

That's how Gao Zhendong started his introductory course on the clamshell air intake here.

"...The key to this clamshell air intake lies in this bulge, which compresses and displaces the boundary layer of the airflow, while also forming a wave system, and at different speeds..."

Gao Zhendong launched into a long speech, and no one dared to interrupt him. Even the comrades from the Air Force Equipment Bureau who didn't understand it listened with great interest. So what if they didn't understand? Even if I didn't understand, I could still keep track of time and read expressions.
The longer it goes on, the more the expressions on the faces of the comrades at the Southwest Institute change, the more reliable the matter becomes! Social engineering knowledge can also be used in technical management and coordination work.

The comrades from the Aircraft Equipment Bureau were right. As Gao Zhendong continued his explanation, the comrades from the Southwest Institute had very varied expressions on their faces.

Shock, admiration, excitement, sudden realization...

Almost every expression a technician has when they find a new path can be seen on their faces.

"...Based on my preliminary calculations, the optimal operating range for this air intake is in the subsonic to Mach 1.6 range..."

With a "buzz," the comrades immediately erupted in excitement. This fixed device, aside from a bulge, had nothing special about it, saving on a partition and numerous adjustment mechanisms, and its optimal working range was surprisingly wide!

Although the requirement for this aircraft is 2.2M, as everyone knows, 2.2M is rarely used, and the optimal operating range does not mean that the performance is unacceptable outside of this operating range. Committee Member Gao would not make such a mistake.

"Mach 1.6! If that's true, this air intake can be passed down like a family heirloom for generations!" exclaimed an excited colleague from the Southwest Institute. He had understood Gao Zhendong's explanation perfectly, except for figures like Mach 1.6 which were still uncertain, but the principle was absolutely correct! This technology has a very broad prospect and is extremely feasible!
That's absolutely true. This thing is even used in trainer aircraft, so it can be passed down for many generations.
Apart from the 27 series aircraft from the White Bear, all other main and non-main fighter jets, from trainers to export aircraft, to the real J-10 modified by Tianya 6 to zero, and to the latest fourth-generation fighter jet, all use it!

"This thing requires virtually no maintenance. Compared to other adjustable air intakes, it's far superior!" The comrade from the Aircraft Equipment Bureau was overjoyed. He was qualified to comment on this; it required no technical expertise whatsoever, and the difference was obvious to the naked eye!

"Not only that, it saves on a series of facilities and mechanisms such as partitions and intake duct adjustments, saving at least one or two hundred kilograms of weight, and greatly reducing the failure rate of the intake system, increasing reliability and availability!"

With the technical staff understanding the explanation and the non-technical staff comprehending it, the comrades excitedly shared their opinions, all of which were good news.

Gao Zhendong smiled and nodded, but then poured cold water on the idea.

"However, this thing also has obvious drawbacks. First, it is very difficult to design. Second, this structure is not very friendly to the air intake of this fuselage with dual air intakes under the fuselage. It is much more friendly to dual air intakes with separate air intakes..."

The design difficulties are self-evident. First, a wind tunnel is needed; second, a computer is required; and third, a large number of people are needed to conduct a large number of experiments. Everyone understands this.

Therefore, the first difficulty that Gao Zhendong mentioned had no impact on the comrades. There was no sense of being hit hard; on the contrary, they felt that this was the normal situation.

Such excellent technology, without paying some price, the comrades would always feel uneasy. Now that the price is here, it makes sense.

(End of this chapter)