Back in 1978, I was admitted to Northwestern Polytechnical University.

Chapter 231 Supply Cut-off? I was just thinking of getting some good quality, inexpensive Eastern goods!
Northwestern Polytechnical University.

A-choo! A-choo!
Qin Liang sneezed several times in a row.

"Liangzi, what's wrong?" Professor Sha looked at Qin Liang with concern.

"It's nothing. I don't know who's been talking badly about me behind my back," Qin Liang said. "Let's continue. Professor Yang, this three-dimensional bulge-type five-surface layer air intake requires very high machining precision. Can our mechanical engineering department's CNC machine tools meet its machining precision requirements?"

Professor Yang nodded: "No problem, Liangzi, don't worry. Our mechanical engineering department's CNC machine tools can definitely meet the machining accuracy requirements. You just need to focus on the design, and we'll solve the machining problems! Once this thing is made, it will be unique in the world and will truly showcase the strength of Northwestern Polytechnical University!"

The design of air intakes is a science. Early nose air intakes were the most efficient, but they couldn't accommodate large-diameter radars, so they were gradually phased out. Side air intakes and belly air intakes gradually became the mainstream. Northwestern Polytechnical University pioneered the two-sided air intake, which was already a revolution.

The air intake not only needs to take in air, but also needs to be able to adjust the amount of air intake. French-made fighter jets often have a cone-shaped part that works in conjunction with the side air intake. This cone is like splitting the nose cone of the MiG-21 in half. At high speeds, it extends forward to block more air intakes and reduce the amount of air intake. After all, the faster the speed, the more air rushes in, and if it is not adjusted, the engine will be overloaded.

In third-generation fighter jets, this method of adjusting the air intake cone gradually disappeared, and was replaced by an adjustable ramp. For example, in the F-15 fighter jet, the upper lip of the obliquely cut rectangular air intake can be adjusted to control different air intake volumes and optimize the position of the shock wave.

The F-16, on the other hand, simply uses a fixed Pitot air intake, which is straightforward and crude. Once the speed exceeds Mach 1.6, the shock wave drag will increase significantly.

Regardless of the type of air intake, it can be seen that it is not connected to the fuselage, but is separated by a certain distance, and an additional plate is added. The function of this plate is boundary layer isolation.

The fuselage surface rubs against the air, causing the air to slow down. Therefore, the airflow speed on the fuselage skin is different from the airflow speed outside the fuselage. The airflow speed of the layer of air close to the fuselage surface is reduced to zero! If this air enters the air intake directly, it will cause serious problems and may even stop the engine. Air with a zero flow speed cannot enter the air intake at all!
Therefore, it needs to be separated from the skin and designed as a separate boundary layer isolation plate.

For high-speed fighter jets, as speed increases, even with the air intake adjusted to its minimum, the air intake volume may still be too large. In such cases, an air venting system needs to be added to the air intake. The J-8 has dedicated air venting valves behind the air intakes on both sides.

Thus, adjustment mechanisms, boundary layer isolation plates, venting systems, and so on are all necessary components of aircraft air intake design! These also increase the weight of the aircraft!
For large aircraft, this doesn't matter, but for small aircraft, this weight must be carefully considered!
In the 1990s, engineers at Lockheed Martin began researching how to eliminate these mechanisms. The result was the DSI (Diverterless Supersonic Inlet), also known as the three-dimensional bulkhead-type non-contact layer diverter intake.
This bulge is essentially a compressed cotton pad that increases pressure distribution and pushes the boundary layer air away from the intake, so you don't have to worry about the boundary layer air, especially the air whose velocity has decreased to zero, interfering with the intake.

Thanks to the use of a conical flow waverider design, the total pressure recovery is high, and since no auxiliary structures are required, the weight can be reduced by several hundred kilograms!
It has a simple structure, is lightweight, has low drag, and is also stealthy, since this bulge can better conceal the engine blades inside!

However, this thing is not ordinary. When it is designed, it requires advanced computer-aided design to carefully design the three-dimensional compression surface and air inlet. At the same time, during production, the shape must also be of high precision. If there is even the slightest error, the effect will be completely lost!

The design task was led by Qin Liang, while the manufacturing task would be handled by the Mechanical Engineering department.

Professor Yang patted his chest and assured him, which put Qin Liang at ease.

Just then, a hearty laugh came from outside: "I heard they're designing the JF-17 Thunder? How far along are they? Hey, what are you designing? Steaming buns?"

"Old Lin?" Qin Liang smiled. "This is a product based on our most advanced design concept, called the DSI air intake. This 'steamed bun' is no ordinary product; it can reduce the weight of the aircraft by several hundred kilograms!"

Old Lin's attitude immediately became serious.

In fighter jets, every gram of weight is crucial. Pilots have to go to the toilet before boarding the plane, and it might just be that one urination that determines the outcome of an air battle. Now, they've actually reduced their weight by several hundred kilograms!
After listening to Qin Liang's brief introduction, the air force personnel all had complex expressions.

In the past, we could only follow in others' footsteps. Now, we are able to lead the world's military aircraft design trend. What does that mean?
"Could this air intake design be used on the J-9 fighter jet?"

Qin Liang shook his head: "If the Air Force emphasizes the interception capabilities of the J-9, then this design is unnecessary."

DSI has many advantages, but also some drawbacks. After all, it is a substitute, and its adjustment capability at supersonic speeds is still not as good as that of traditional adjustment mechanisms. In later generations, after the J-10 adopted the bump air intake, its maximum speed and other properties decreased. However, the J-10's interception capability was no longer very important, and later generations placed more emphasis on multi-functionality.

The current J-9 still uses the WP-15 turbojet engine. The Air Force still needs high-speed interception capabilities to deal with the Russian bear in the north, so it is not suitable to modify it with a bulge.

The key issue is that we don't even know if the technology is mature enough! If it's not mature, then the JF-17's performance might be a bit lacking, but the J-9 can't afford any mishaps!

Old Lin only mentioned it briefly, and since Qin Liang said it wouldn't work, he didn't insist anymore.

"Come on, tell us about this aircraft."

So Qin Liang started with the overall design and talked on and on for more than half an hour, which made Old Lin nod repeatedly.

"Excellent, excellent! This aircraft's design concept is very advanced, our Air Force..."

"Old Lin, our air force should just order some Super-7s. That way, we can keep up with demand until the J-9 enters service. As for the JF-17, it was designed as a light fighter jet for export, suitable for small countries. Our country has a vast territory and needs medium or even heavy fighter jets!"

"You mean something like the dual-engine Type 6?" Old Lin asked.

Qin Liang continued to shake his head: "No, no, the twin-engine Q-6 is positioned as a ground attack aircraft. The advantages brought by the variable-sweep wing are that it can achieve high-altitude and high-speed, as well as low-altitude and high-speed. If you want to save fuel, you can use the Spey; if you want power, you can use the WP-15 turbojet engine, maximizing the use of the variable-sweep wing. But as for fighter jets... times have changed!"

Variable sweep wings are a technology of second-generation aircraft, third-generation aircraft use leading-edge extensions and blended wing-body technology, and fourth-generation aircraft are stealth aircraft. After the J-9 was developed, the next step was to develop a fourth-generation heavy stealth aircraft!
"Tell me more about it?"

"I believe that after the J-9's maiden flight, the development of a fourth-generation twin-engine heavy stealth fighter should be put on the agenda. We have various technological reserves and are fully capable of developing such an aircraft. As for the engine, it's not a problem if it's a little weak now. At worst, we can continue to use two turbojet engines and replace them with advanced turbofan engines when they become available..."

The combination of canards and leading-edge extensions, internal weapons bays, diamond-shaped nose, and outward-canted twin vertical tails...

When these design proposals were shared, Old Lin felt as if a new door had opened in his world!
"This design sounds incredibly impressive!" Old Lin nodded.

"Yes, we're catching up in third-generation fighters, but in fourth-generation fighters, we've surpassed them! What I just mentioned was the shape, but electronic equipment is even more important, especially radar. We need to develop advanced active phased array radar modules as soon as possible..."

Northwestern Polytechnical University (NPU) has made a lot of money, but they have invested it in research and development of various technologies! The development of the Air Force's equipment depends on NPU!

"Before 1989, our fourth-generation fighter jet needed to make its maiden flight. By the 1990s, our air force's equipment would definitely be number one in the world, and we would be fearless of any threat!"

89 was a crucial turning point! Before that, we had good relations with the West and could import all sorts of products. After that point, we became so strong that the West was wary of us! They still couldn't do anything to us!
Old Lin nodded: "Good, just for what you said, our Air Force will give it our full support! Once the J-9 makes its maiden flight, our Air Force will hold a bidding conference for fourth-generation fighters! Now... shouldn't we first explain these basic theories to the other design units so they can also prepare?"

"Of course," Qin Liang nodded.

Actually, it's useless to say anything. After all, the design can only be done by Northwestern Polytechnical University, and the selection of partner units is still 611. Other units bidding are just going through the motions and playing a supporting role. However, it is really necessary to go through this process. Only in this way can we shut some people up. Not to mention, the senior members of the aircraft design institute will cry and shout that it is unfair.

Before they knew it, dusk had fallen, and the setting sun painted the sky red. Qin Liang rubbed his rumbling stomach and asked, "Old Lin, shall we go eat?"

"Let's go eat together, and maybe have a few drinks!"

"Another drink!" Qin Liang felt a chill. "Report! News has come from Pakistan: the UK has officially notified us of the termination of Pakistan's purchase of Skyflash missiles!"

Qin Liang smiled. These Americans had indeed gone to Britain to deceive people again, and the British were really obedient, loyally serving as the Americans' little brothers, not caring even if it affected their business!
"Liangzi, you were right! Why are the British so obedient to the Americans?"

"Yes, what happened to the dignity of the former British Empire?"

"When a powerful force is conquered by another powerful force, it is more satisfying for them to kneel down. After World War II, Britain completely became America's lackey, which is not surprising. Moreover, if I am not mistaken, although the British lost their business with Pakistan, their active air-to-ground missile seeker technology was definitely purchased by the Americans. Their business losses were filled by the Americans."

Everyone was stunned.

British aerospace company.

“Mr. Chiralk, we have informed Pakistan of the termination of the supply of Skyflash missiles. Currently, less than one hundred of these missiles have arrived, enough for only one squadron. They will soon face a shortage of medium-range air-to-air missiles,” Herman, the head of the power department, said to Chiralk with a smile.

"Yes, you've made the right choice!" Chiralk said. "Pakistan's comprehensive purchase of Eastern weapons is of no benefit to the United States. We must suppress them and let them know that they only have a future if they rely on the United States!"

Chiralk was very optimistic. Although he still didn't know what kind of missile shot down the MiG-25, the Skyflash missile was definitely a high-performance medium-range air-to-air missile. Without it, Pakistan's Super-7 fighter jets were like having guns but no bullets!

Pakistan must return to the embrace of the United States! It must reduce its dependence on the East!
As for fighter jets, we must purchase F-16s; at worst, we can just increase their medium-range missile carrying capacity!
Anyway, the F-16 is constantly being improved, and increasing its medium-range interception capability is also within the scope of these improvements.

"In compensation, we in the United States will introduce your relevant technologies to upgrade our AIM-7, with the new model named AIM-7M. We will also work with you to further research active radar-guided medium-range air-to-air missiles. The development of such a missile will change the history of air combat worldwide!"

In this respect, the Americans were indeed lagging behind. Their first missile with look-down and fire-down capability was the AIM-7F, but unfortunately, its performance was still very poor. In 1982, the AIM-7M officially entered service. This missile used almost the same technology as Skyflash, including a reverse monopulse seeker, digital control circuits, radio proximity fuses, and so on.

Now, there's no need to develop it ourselves; we can directly purchase it from British Aerospace and equip the troops with it as soon as possible. Otherwise, if even third-world countries have it and the United States doesn't, wouldn't that be too embarrassing?

"Great!" Herman exclaimed excitedly.

They do indeed have this plan!
Semi-active radar-guided missiles require the carrier aircraft to continuously illuminate the target until it hits, which is a threat to the carrier aircraft. Active radar-guided missiles can withdraw midway and leave the final attack phase to the missile itself, making it difficult for the enemy to defend against!

It would cost them a fortune to develop it themselves, so the opportunity to collaborate with the United States is something they would be very happy to have!
In his excitement, Herman thought of something else and cautiously asked, "Speaking of which, could the Easterners possibly develop a similar medium-range air-to-air missile?"

"How could that be! Eastern technology is outdated. Although they've used clever tricks to create aircraft like the Super-7, they're still far behind overall! Their capabilities are limited to improving aircraft; advanced air-to-air missiles? Hmph, they don't have that capability!"

Ba Kingdom.

"First the Python-3, then the Skyflash—the Americans are clearly trying to pressure us into buying their F-16s!" General Haidar exclaimed angrily. "This is outrageous!"

“Yes, the JF-17 is our best option. The money we spend on one F-16 can buy two JF-17s. Pakistan’s economy is weak, so we have to take the low-cost route. These Americans are too greedy!” Sabil was furious. “Not to mention, we can produce the JF-17 ourselves, which is more meaningful than purchasing it directly!”

In short, the Americans were forcing them to accept an aircraft they didn't like! That way, all the military aid money would end up in the Americans' pockets!

"Fortunately, General Dynamics and General Electric are not the same company, otherwise, we might not even be able to procure the F404 engine."

"Yes!"

Everyone looked dejected, but Jamal, sitting in the main seat, showed no sign of tension.

Noticing his appearance, the others became somewhat curious.

"General Jamal, do you already have a solution?"

"Gentlemen, have you all forgotten what happened when our Super-7 fighter jet first tested its Sky Flash?"

Everyone was taken aback, then it dawned on them.

“Our friends in the East have long anticipated the possible schemes the West might be plotting,” Jamal said. “If the British continue to supply missiles, then we will continue to purchase them from them. If the British stop supplying them, then we will purchase them directly from the East!”

"The East has it too?"

"Definitely! In fact, its performance might even be better than the original! And it'll be cheaper!"

"Alright, then I'll go to the East right away!" Haidar said. When he was test-flying the J-8, he only paid attention to the long-range air-to-air missiles and completely overlooked the other missiles mounted on the outside of the J-8's wings. Those were clearly medium-range air-to-air missiles and short-range dogfight missiles produced by the East itself!

"Report! Our friends from the East have arrived!"

Manager Liu entered Old Ba's Air Force Command with a big smile on his face.

"Gentlemen, I am truly sorry. I did not expect such an unexpected turn of events. At the Paris Air Show, we had already finalized the purchase of air-to-air missiles. These Westerners are really unreliable. I brought with me information on our domestically produced Lightning-10 and Lightning-9 missiles. These missiles can fully meet your needs!"

This kind of thing no longer requires Qin Liang to personally handle; Manager Liu can resolve it.

"Yes, Manager Liu, we were just thinking of going to Dongfang to take a look, and we didn't expect you to come to our door like this." Jamal said with a big smile, "Come on, tell us about it!"

Manager Liu took out technical documents, one for each person, and they looked at them while Manager Liu explained them.

"Let's start with the medium-range missile, codenamed Lightning-10. Compared to Skyflash, this missile has upgraded its propellant technology, increasing its maximum range by about ten kilometers. The internal circuitry of the warhead has been optimized, and it extensively utilizes digital technology, making it the most resistant to interference... As for the price, it's two hundred thousand US dollars per missile."

The money spent on short-range Sidewinder missiles could buy medium-range missiles!
"Let's look at the short-range missile, codenamed Lightning 9. When used with a helmet-mounted sight, it has the capability to preemptively launch missiles for kills. Compared to the Python-3, its off-axis launch capability has been further improved to 45 degrees, and it is also equipped with a vector thrust device, which can turn towards the target as quickly as possible..."

"Alright, let's each buy five hundred first. We've been wanting to cancel this Western order for a while now!"

　PS: Images of the F-15's air intake adjustment plate and DSI bulge air intake.

　　
　
(End of this chapter)