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

Chapter 399 Busy Fourth-Generation Fighter Jet Development
Several people came up and pulled Xing Youguang away.

"Engineer Xing, calm down, calm down!"

Xing Youguang squatted down weakly, making a whimpering sound.

"Huizi, my Huizi! You...you..."

The other people also had mixed feelings.

"Mr. Xing, don't be sad. After all, Keiko Waseda did it all for..."

Xing Youguang raised his head, his gaze turning angry again. So, Dean Huang could only swallow his words of comfort; it really wasn't appropriate to say anything more now.

Although two spies were exposed, at least they obtained the technical information!
With this information, their IDF fighter jet development can proceed smoothly!
“Old Xing, you’re not fit to work lately. I’ll give you a few days off first, you…” Peng Yuanxi started to speak, then quickly shut up. Xing Youguang looked at him, and the look in his eyes sent chills down his spine.

"No, I need to work, I can't let my daughter's sacrifices be in vain!"

Everyone breathed a sigh of relief.

From that day on, Xing Youguang entered a frenzied work mode. When he received news from the mainland that 3450 and 3451 had been sentenced to life imprisonment, he didn't feel much. He was as if he had become numb and devoted all his energy to the trial production.

This place was already capable of manufacturing light trainer aircraft; it had all the necessary production equipment. By following the blueprints, the airframe parts were quickly produced, and the final assembly process began.

"Regarding avionics, we have reached an agreement with the United States on the AN/APG-67 radar. They will not only provide the finished product, but also authorize us to produce it. We will name it Jinlong 53," Hu Jin, the chief engineer in charge of avionics, reported to everyone.

"Regarding the engine, with technical support from the mainland, Garrett has completed all the experimental work for the modified engine. Now, they have entered the low-speed production stage and can send us the first batch of engines. To avoid any accidents, the engine model is still TFE731," said Zhang Xuebin, the chief engineer in charge of the engine.

"Everyone, let's seize the time and work hard to complete the assembly of the aircraft as soon as possible and launch the maiden flight at the earliest opportunity!" Dean Huang said with great excitement.

Thanks to the technical support from Northwestern Polytechnical University, otherwise, they would never have been able to manufacture a prototype in such a short time!
"Dean Huang, we're currently producing two-seater aircraft. Shouldn't we start developing single-seater aircraft next?" Peng Yuanxi asked.

When cooperating with the East, the pretext used was that it was a trainer aircraft, so now, this aircraft is a two-seat model! In the future, the real fighter jets will still be mainly single-seat, and the two-seat models will mainly be used as formation leader aircraft and for training pilots.

"Once the two-seater aircraft makes its maiden flight, we will develop a single-seater aircraft!" Huang Xiaozong said.

"Ok."

It's already July, and Northwestern Polytechnical University's graduate admissions have come to a successful conclusion, with the list posted outside the office building.

Now, this is Building No. 1, located in the southwest corner of Northwestern Polytechnical University. It originally belonged to the main building of the university, but... as each department has its own building, fewer and fewer departments are holding classes in the main building. As a result, the main building has been transformed into the most important office building of the university.

Once, this building was magnificent and the best building in the school. Now, compared to those buildings, this building looks somewhat dilapidated. Although there are plans to renovate it this summer, such as repainting the exterior walls, it still cannot hide its sense of desolation.

At this moment, the place is very lively.

"Brother Da Ming, you passed the exam!" Qin Liang squeezed through the crowd and said to the people behind him, "You ranked in the top three in the exam and have been admitted to the Fifth Department. Next, you'll need to have an interview. However, Professor Liu, your advisor, has worked with us before, so there won't be any problems with him. Come on, I'll take you there now to talk to your advisor!"

When Qin Liang first entered Northwestern Polytechnical University, he had a lot of contact with Professor Liu, starting with Green's function and then moving on to other projects... Professor Liu is a well-known expert in aerodynamics and flight mechanics in China, and in recent years, with the help of advanced research technology, he has made further progress!
When Director Luo was promoted to president, Professor Liu was nominated to be the head of the fifth department. However... Professor Liu refused. He didn't want to do administration, he only wanted to do scientific research. So, he became the nominal head of the department and continued to do scientific research.

Now, Professor Liu's main focus is, of course, the combination of stealth aircraft shape and aerodynamics! This is a seed that Qin Liang planted back then, when Professor Liu could only stand there and pretend, and all the introductions relied on Qin Liang.

Over the past few years, Professor Liu has been deeply involved in this field and has become a leading expert in it!

Qin Liang led Qin Ming to the Fifth Department Building, where they met Professor Liu, who was engrossed in his work, in the computer room.

"Professor Liu!"

"Um, wait a minute, let me finish writing this program... Hmm? Liangzi?"

Upon discovering that the visitor was Qin Liang, Professor Liu immediately put down his work: "Come on, Liangzi, let's go to my office next door and have a cup of tea!"

Qin Ming followed behind, marveling at Qin Liang's special status at Northwestern Polytechnical University; he was practically the uncrowned king of the university!
Inside the office, Qin Liang held a teacup and looked at Qin Ming, who was standing awkwardly to the side, completely ignored.

"Professor Liu, this student Qin Ming has been admitted to our Northwestern Polytechnical University's doctoral program this year. Next, he will be interviewed and selected a supervisor. Could you... be his supervisor?"

"Yes, of course, no problem. Qin Ming has a solid foundation and has performed well in previous projects. He can certainly work for me..." Professor Liu thought for a moment and said, "Da Ming, perfect timing! I have a research and development project here that I'll entrust to you!"

"What project?" Qin Ming's eyes were full of anticipation. The project was still under development, so it must be the most advanced in the world.

"Aerodynamic analysis of the Garrett intake".

Since the advent of the jet age, the study of air intakes has become an important topic.

Those sling-mounted engines don't need air intakes; you can see the fan blades directly in front. This makes the engine most efficient, but... it's not suitable for fighter jets! How can a fighter jet perform high-G maneuvers with such a large engine mounted on its wing? The wing might be torn apart!
After years of research, it has become a consensus that fighter jet engines should be located at the tail, while air intakes should be at the front, thus requiring dedicated air intake ducts.

First-generation fighter jets almost always had nose-mounted air intakes, which maximized air intake efficiency and prevented the air intake from getting blocked under various conditions. This was the most common method in the era of subsonic fighter jets.

However, this method cannot install radar in the nose. As airborne radar becomes more and more important, the air intakes began to move to the sides of the fuselage. At the same time, as fighter jets entered the supersonic era, the airflow required by the engine is different at different speeds. At this time, adjustment devices are needed.

The earliest type was the air intake cone, such as the nose air intake cone of the MiG-21 and the side air intake cones of the Mirage 3. These are the most common adjustment methods.

With air intakes on both sides, one air intake will be blocked when the aircraft turns. Third-generation aircraft pursue high angle of attack performance, so ventral air intake has gradually become the mainstream. At the same time, the adjustment device has also become an adjustable compression ramp design. However, as long as there is an adjustment device, it will inevitably increase the structural weight.

At the same time, because the gas flow rate on the surface of the aircraft will decrease, the air intake and the aircraft will have to be separated. This is a boundary layer separation baffle, which will also increase the weight of the aircraft.

Therefore, when the JF-17 was being developed, Qin Liang proposed the DSI bump-type air intake. This air intake has been developed to a mature stage on the JF-17. However... after discovering that the West had begun to study the Garrett air intake, Professor Liu believed that it was still necessary to study this type of air intake as well.

When the era of stealth aircraft arrived, the air intake was also optimized, with two main technological achievements.

First, the F-22 was born, and it used the Garrett intake, which is translated into Chinese as swept-back double-sloping supersonic intake. Generally speaking, this intake is located on both sides, but it looks like it is suspended on the side.

It has two three-dimensional ramps distributed along the air intake, which rationally distribute the intake airflow velocity, thereby reducing the supersonic airflow to subsonic speed with minimal loss. It has no adjustment mechanism and a very simple structure.

Northwestern Polytechnical University is currently developing various advanced aviation technologies, and this type of air intake has also been included in its research scope.

Qin Ming took a deep breath: "Okay, I can take on this research and development task! Teacher, do I need any reference materials?"

"Okay, I'll give you a list here. If you're free, you can start studying it today."

"it is good!"

Qin Ming left with a stack of books. Watching his departing figure, Qin Liang felt complicated. He had planned to tell Da Ming about Waseda Keiko after his exams were over and he was officially admitted. Unexpectedly, Da Ming hadn't even thought of Waseda Keiko!

This……

Whoever marries Brother Da Ming is incredibly unlucky! However... from the perspective of continuing the Qin family line, Brother Da Ming still needs to get married.

“Liangzi, Da Ming’s wife’s situation does have an impact, so we can’t let him access our core secrets for now,” Professor Liu said. Qin Liang nodded: “Yes, Professor Liu, of course I know. It’s good enough that Brother Da Ming has a project to develop. This project could totally serve as his doctoral dissertation, although we won’t need it…”

"You don't think this kind of air intake is good?"

"Yes, it's a level below our bulge-shaped air intake, but... it's still far superior to other air intakes of this era."

Professor Liu nodded: "Well, then we'll stick with the bulge-shaped air intake."

"By the way, what preparations have we made regarding fourth-generation stealth aircraft?"

"Of course!" Professor Liu nodded: "Yang Wei and the others came over after the meeting in the capital. Old Song also comes from the flight test institute from time to time to help with the planning. The preliminary design of the shape is currently being tested in the wind tunnel."

"So fast?"

"Yes, they've been using our most advanced supercomputer, often spending a whole week calculating... However, Yang Wei and his team applied for a master's thesis project, which is a research project at Northwestern Polytechnical University, so we can only let them use it."

Qin Liang exclaimed excitedly, "Okay, I'll go take a look!"

Northwestern Polytechnical University, Wind Tunnel Laboratory.

The previous wind tunnel test had just ended, the wind tunnel was opened, and the model was taken out of the wind tunnel.

"This design is indeed flawless. The canards, strakes, and delta wings combined will definitely create the most powerful fighter jet!" Yang Wei exclaimed excitedly.

"Yes, Comrade Qin Liang's suggestion is entirely reliable. However, this makes the aerodynamic layout more complex and cumbersome, and places higher demands on the programming of the flight control system," Old Song remarked.

"It's alright, Mr. Song, leave the flight control to me!" Yang Wei said. "I'll make it as mature and reliable as the flight control system of the J-9!"

"Ok!"

"Everyone, where's the model? Let me see it!" Just then, a familiar voice rang out from outside.

"Qin Liang!"

"Brother!"

Amidst the excitement of the group, Qin Liang looked at the model that had just been taken out.

The nose is diamond-shaped, with a bubble cockpit above and a parallelogram-shaped air intake below, somewhat similar to the Garrett. However, the bulge surrounding the air intake is particularly noticeable. Behind it are leading-edge extensions, main wings, and outward-canted twin vertical stabilizers...

This plane is really beautiful. It already has a 90% resemblance to the J-20 of later generations!

"Liangzi, what do you think of the shape of our plane?"

"Yes, not bad. None of the products developed by our Institute 611 are bad!"

"Ahem, actually, it's mainly thanks to the great efforts of Northwestern Polytechnical University. We took a twin-engine, twin-tail project from the previous J-9 project, input it into the computer as raw data, and made a lot of improvements. If it weren't for Northwestern Polytechnical University's top-notch computers, we definitely wouldn't have been able to develop it so quickly."

"Professor Song, please don't say that out loud," Qin Liang said. "Other units will be unhappy, especially the Northern Institute. They'll accuse us of favoritism."

"They're not stupid. They know they don't have the skills, so they went to Shenyang Aerospace University to collaborate with the university. This model is very popular in China now."

Universities have technology, factories have capital; the two can form a powerful alliance!

Actually, the Northern Institute first approached Beihang University, after all, it is the strongest aerospace university in China, cough cough, the strongest on the surface. However, Beihang University said that it did not have the capability, and they had several cooperative projects with Northwestern Polytechnical University.

So, after returning to the Northern Institute, he went to Shenhang University, since there were also aerospace universities in his city!

In 1952, Shenyang Aviation Industry School began construction, becoming one of the six aviation industry schools in China. This university has also made many innovations, such as the Shenhang No. 1 general aviation aircraft, which they manufactured and successfully took to the skies of the motherland.

During that special era, Shenyang Aerospace University was renamed Factory 251, which specialized in producing aviation electromagnetic instruments. It remained until 72 when the university resumed operations, while Factory 251 continued to exist as an affiliated factory of the university. In 1978, the university was transformed into a regular institution of higher learning and renamed Shenyang Aerospace University.

More importantly, just last year, more than a dozen students from the first batch of graduates from the three graduating classes of Northwestern Polytechnical University were recruited by Shenyang Aerospace University to become teachers. These teachers quickly became the backbone of Shenyang Aerospace University! Shenyang Aerospace University also began to learn from Northwestern Polytechnical University, focusing on teaching and scientific research, hoping to transform itself again.

At this time of year, the climate in Shenyang is very pleasant, cool and dry, and not hot at all.

In Shenyang Aerospace University's computer room, countless heads surged.

"Our calculations show that conventional aerodynamic layouts have many problems, especially the trailing edge of the wing, which greatly increases the radar cross-section." Wang Xiaoqiang, who came from Northwestern Polytechnical University and is now a young backbone teacher, looked at the data on the computer with some helplessness.

"The Air Force only requested the frontal radar cross-section specification; they didn't specify the side or rear dimensions. Let's solve the frontal issue first; we'll deal with the side and rear dimensions later!" Engineer Li waved his hand.

"no!"

"why?"

"The front is definitely the most important area, and it must be reduced to 0.01 square meters. However, the sides and back cannot be ignored either; they can be increased by an order of magnitude to 0.1 square meters. As it is now, the reflective area has exceeded 1 square meter, which is absolutely unacceptable!" Wang Xiaoqiang's attitude was firm: "If we at Shenyang Aerospace Engineering Group are going to design it, then we must solve these problems. We will not be involved in defective products!"

"you!"

Engineer Li looked grim.

Time is of the essence now. If we don't quickly design the shape and submit it for bidding, we may completely lose this opportunity! If the fourth-generation fighter jet development project doesn't go to their Northern Institute, they will completely decline!
“To reduce the radar cross-section, the trailing edge cannot be perpendicular to the fuselage, as this maximizes the radar cross-section. Do you think we could sweep the trailing edge forward to reduce the radar cross-section?” Wang Xiaoqiang said after pondering for a moment.

“We’ve never seen anything like this anywhere in the world!” Engineer Li shook his head. “We can’t take risks. Our institute in the north must prioritize stability.”

The popular third-generation fighter jets feature clipped delta wings with swept-back leading edges and trailing edges perpendicular to the fuselage. No one in the world has ever seen a wing with a swept-back trailing edge. Wouldn't that just be the layout of a straight-wing aircraft from World War II?

"Seeking stability? How can we progress if we seek stability? How can we surpass others if we seek stability? Without innovation, how can we reach the world's number one?" Wang Xiaoqiang's expression also became serious.

After coming into contact with people from the Northern Institute, he felt very uncomfortable.

At Northwestern Polytechnical University, everything is about innovation; whoever dares to innovate will receive strong support. But here, everything is about stability!
Seeking stability will only lead to forever following in others' footsteps!
"Engineer Li, forgive my bluntness, but if it's not modified, then this kind of aircraft is garbage! I, Wang Xiaoqiang, would rather withdraw from this research and development project and focus on teaching than work on a garbage project!"

After saying that, Wang Xiaoqiang stood up: "You can choose for yourselves!"

"and many more!"

Seeing that Wang Xiaoqiang had already reached the door, Engineer Li had no choice but to change his mind: "Then let's try the plan you suggested?"

Although Wang Xiaoqiang was not a student in the famous Class 5381, he was from the class next door and had top grades. At Northwestern Polytechnical University, he had also worked under Professor Liu on the research and development of stealth technology.

It's fair to say that if Wang Xiaoqiang left this project, they wouldn't be able to accomplish anything! The Northern Institute simply doesn't have the relevant technological reserves!
"Okay, let's continue."

(End of this chapter)