Chapter 570 Il-76 and Yun-20
One of the important reasons for the establishment of the Yunwen 20 project is the demand of the Air Force, including early warning aircraft, tankers, and ordinary transport aircraft. These needs are all looking forward to the emergence of large aircraft.
In China, XAC manufactures large aircraft. The Yunba was originally surveyed and mapped by the 603 Institute and then handed over to XAC for production. Now, after the 603 Institute has built the Feibao, it is also looking forward to developing a large aircraft project. .
Since there is no project, it has been conducting self-research. Now, if the Air Force wants to obtain strategic transportation capabilities, it must have a large transport aircraft produced by itself!
At this time, hearing Mr. Lin say this, everyone present became excited.
Qin Tao also felt very excited.
Originally, Qin Tao came here to participate in the emergency response after the Falcon early warning aircraft project was stopped. However, because he was prepared in advance, the topic of this meeting quickly changed.
If you want to completely solve the problem of early warning aircraft, you still have to have your own airframe platform!
“However, it is not easy for us to independently develop a large aircraft. Whether it is an engine, aerodynamic layout, or even a simple landing gear, it is all blank for us.” A leader at the scene spoke.
“Yes, even if the 603 Institute conducts preliminary research, there will still be a lot of road ahead.” Another leader said.
"Mr. Qin, do you have any ideas?" Mr. Lin looked at Qin Tao.
Qin Tao reacted instantly. Although he was a shipbuilder, his relationship with the Air Force was getting deeper and deeper. On such a major issue of military equipment development, Mr. Lin still wanted to seek his opinion.
"First of all, the biggest problem in the large aircraft project is the engine." Qin Tao also said: "Except for the turbofan-15, other products in our country are currently immature. Therefore, if you want to establish a large aircraft project at the same time, , and the high-bypass-ratio turbofan engines specially designed for large aircraft will definitely not be used in time. "
There has always been a shortage of aircraft cores in China. The rapid maturity of the J-31A is related to Qin Tao's promotion. All the engine data of the R-79 were purchased, including the production and processing technology of various blank materials, and It can be said that all kinds of equipment are the same as when industrialization was achieved with the help of Lao Maozi in the first Five-Year Plan, so the imitation of the WS-15 did not encounter any problems.
But the others are different.
Both the J-10 and J-11 are looking forward to using the turbofan X-10, but this engine is still far away from success.
If you launch a large aircraft, you must have a special engine. This kind of engine is different from that used in fighter jets. In addition to the difference in the afterburner, it is the bypass ratio.
The turbofan engine is equivalent to putting an outer duct on the outside of the turbojet engine and blowing air directly behind it, thereby increasing thrust and reducing fuel consumption. However, fighter engines also have to consider the windward area, so the bypass ratio generally does not exceed 1.
The transport aircraft is different. The larger the bypass ratio, the more fuel-efficient it is. As for the increase in the windward area, the problem is not considered. Transport aircraft do not need supersonic speed anyway.
The D-30KP-2 engine on Lao Maozi's IL-76 has a bypass ratio of 2.4, while the turbofan-20 independently developed in later generations has a bypass ratio of more than 4, and the bypass ratio of passenger aircraft engines is even lower. More than ten!
There is no technical reserve in China.
“When our Turbofan 10 research and development matures, we can add a large outer duct to the core engine of the Turbofan 10 to become the engine of the transport aircraft.” A leader of the Air Force said.
“Yes, if the progress of WS-10 continues to be delayed, we can still make changes to the core machine of WS-15.”
Everyone put forward their opinions one after another.
Although the engines are different, the core machines can be exactly the same. This is what the West does.
"The engine can be developed on our core aircraft, but it will still take a long time to develop. Therefore, if we want to build a large aircraft, we can first purchase the D-30K engine from Lao Maozi and use it on our transport aircraft. Anyway, our Relevant units are already using this engine to improve the H-6," Qin Tao said.
For a long time, the H-6 was the only heavy bomber in China. Because of its high take-off weight, it was even converted into an aerial tanker for supporting use by the J-8.
The turbojet-8 originally used by this aircraft had high fuel consumption and weak thrust. After the collapse of the Red Empire, relevant units began to study using Lao Maozi's engine to replace it.
Of course, this improvement has still caused headaches for technicians for a long time. After all, the diameter of the D-30KP2 turbofan engine planned to be modified is 20 cm larger than the turbojet-8 engine, and the air intake requirements have also increased. The power cabin needed to be modified, and the inlet and tail nozzle had to be widened, so the D-30KP2 turbofan engine was barely installed.
Because the engine power is so strong, the thrust has to be reduced on the H-6.
As the official engine of the IL-76, Qin Tao put forward his first opinion: If we want to build a large aircraft, we must have an engine. Under the premise that our own engine is immature, we must first purchase Lao Maozi's engine.
Moreover, since transport aircraft all use pods, it is easier to change engines. In later generations, there was a similar scene: three of the four engines were the same size, but one of them was a lot thicker. , because this one is made in China and the other three are from Lao Maozi.
“That’s right, we can’t wait. Just like the J-10, we will use imported engines first, wait until the performance of domestically produced engines stabilizes, and then replace them with domestically produced engines.” Mr. Lin nodded immediately.
“The next step is to develop the airframe. Lao Maozi’s Il-76 is very good. I suggest you refer to the design of the Il-76.”
After the Y-20 came out, its appearance was very similar to the IL-76, so much so that it was said to be a copycat, and the names of it became Loma, Shen Hoy, and Silyushin also spread.
In fact, the reference must have been made, but it is still different in many places. The body of the Y-20 is wider, and the tracks do not need to be removed when transporting the tank. The wing shape of the Y-20 is also very different from that of the IL-76.
It is normal to learn from foreign aircraft. After all, the IL-76 is a very mature transport aircraft. Of course we must take its essence and discard its dross! It can be said that even if it is copied, it is still quite good. If it is improved, it will be even better.
Now, if 603 is to be carried out, it must be referred to.
"Now, the IL-76s equipped in our army are very precious, and they must not be taken out to be dismantled by the 603 Institute for surveying." Mr. Lin said to Qin Tao: "Mr. Qin, is there any way you can get the IL-76s?" -76 design information?”
Qin Tao came to his senses. I'm afraid this was the main purpose of Mr. Lin calling him here!
Whether it is the navy or the air force, they all need large aircraft. Such aircraft cannot be completely relied on outsourcing. No matter how many they are purchased from outside, they will not be enough. They can only be developed by themselves.
For a country that has never developed a large aircraft, the best way is to survey and imitate it, and then improve it. However, surveying and imitation requires the provision of a prototype. With the current amount of domestic equipment, providing a prototype is too luxurious. Therefore, the Air Force put the idea on Qin Tao's head, hoping that Qin Tao could help.
After all, this kind of thing has been done more than once.
"The information on the IL-76 mainly exists in two places. The Ilyushin Design Bureau must have a complete set of information, but it is too difficult to get the information from them. It can only be purchased through formal channels. The price is It will also be very expensive." Qin Tao said: "The other place is the Chkalov Aircraft Factory."
"Yes, Mr. Qin, we think so too. As long as we operate well, we can package the Il-76 information back from the Chkalov Aircraft Factory." Mr. Lin said, "However, this kind of thing You’re still the best at it.”
Qin Tao has done similar things many times, and of course he is familiar with it.
Hearing what Mr. Lin said, Qin Tao could only smile and nod: "I can go and try."
Facing the issue of the Kingdom of David breaking up the contract is still secondary. Next, it is important for our country to independently produce advanced large transport aircraft.
Qin Tao has been to the Chkalov Aircraft Factory more than once, but he has been in China in the past year or two, so he doesn’t know if the people there have changed. However, since last year, the Chkalov Aircraft Factory has almost It is in a state of shutdown, so the situation there must be very difficult.
“You guys always find things for me to do before the Chinese New Year.” Qin Tao complained again.
"This is also for the navy. The navy also needs a large number of transport aircraft. If we can develop our own transport aircraft, then the navy and air force will be able to equip a large number of them." Mr. Lin said with a smile.
“Then try to finish these things before the Spring Festival. I first need to go to the 603 Institute and go there with the experts.”
A heavy snowfall a few days ago made the entire land covered with snow. Mr. Chen stood in the snow with a smile to welcome Qin Tao's arrival.
"Mr. Qin, welcome to our 603 Institute for inspection." Mr. Chen extended his hand enthusiastically.
“Mr. Chen, why are you running out at such an old age? Come on, let’s go in quickly.” Qin Tao just shook his hand politely and hurriedly urged.
"Mr. Qin, you are too disrespectful. I am an old man with a strong body." Mr. Chen was not polite, and his words were casual and kind.
In the howling north wind, a group of people walked into the conference room.
"Mr. Qin, at the Zhuhai Air Show last time, your words were inspiring and pointed out the direction for us. Next, we already have the direction to improve the Flying Leopard fighter-bomber. We do not pursue stealth capabilities, just Pursue the improvement of its low-altitude penetration capabilities." Sitting in his seat, Mr. Chen continued to speak.
“Actually, we also need stealth bombers, but we must develop them from scratch, and we must not improve on the existing Flying Leopard fighter-bombers.”
Qin Tao's words immediately heated up the atmosphere at the scene. A middle-aged man in his thirties or forties asked: "Mr. Qin, what kind of stealth bomber do we need? Is it like the F-117? 伱The ability of our J-31A fighter plane to carry bombs is almost the same as this kind of aircraft, right?"
The J-31A's built-in pylon cannot carry too many weapons and equipment, but it is no problem to install two bombs. The F-117 is at this level.
"Of course not. Although the F-117 has an F prefix, it is actually an out-and-out attack aircraft. What we are talking about now is a bomber." Qin Tao said: "With the American B-2 stealth bomber The same big bomber.”
(Some readers said before that the B-2 was released in 1988. Heroes of East China searched for it and found this news. However, I am a little curious as to how the Americans could have such a strategic-level killer weapon so early. Open to the public, it seems that he only entered service in 1989. Are Americans so impatient?)
After the B-2 bomber was released, it almost became a sensation around the world. Although aircraft designers studied the flying-wing layout during World War II, until modern times, there has never been such an aircraft that has been put into service. Especially, this This bomber also canceled the vertical tail, so many aircraft designers felt that it was impossible for this aircraft to fly.
Now, when Qin Tao mentioned this bomber, everyone took a deep breath. This technological leap is too big.
“Of course, this is the direction of future efforts. We don’t need this kind of bomber yet.”
The B-2 is a strategic bomber of this level. It can fly around the world when deployed at bases in its own country, bombing any country and then flying back. Currently, the East still has a defensive policy, so there is no need for such a big killer.
At this time, everyone nodded when they heard what Qin Tao said. If they were allowed to develop this kind of aircraft, it would be too difficult and impossible to conquer in a short time.
This can be a development direction in the future, but there is no need to consider it so much now.
"Now, let's talk about transport aircraft. This is a big thing that the Air Force is in urgent need of. I plan to go to the Chkalov Aircraft Factory this time, and I need someone to accompany me." Qin Tao said: " I wonder if any of you are free?"
Currently, the 603 Institute is still working tirelessly on the Flying Leopard fighter-bomber project. As for the Il-76-class large transport aircraft, it does not have much power yet. At this time, after hearing Qin Tao's words, Mr. Chen said: "Xiao Tang has been doing preliminary research on this project. You can take him with you."
"Yes, Mr. Qin, I am willing to go with you." said the middle-aged man who just spoke.
He is already thirty or forty years old, but in Chen Lao's mouth, he still screams "Little Tang", which Qin Tao also felt was a little funny.
Tang Changhong was born in 1959. In 1978, he became a new third-year college student who resumed the college entrance examination. He studied aerodynamics at Northwestern Polytechnical University. Currently, Yang Wei, a rising star in 611, is his bunk roommate. After that, he entered 603 Institute and served as the leader of the professional team. During this period, he went to Capital University of Aeronautics and Astronautics to study solid mechanics and received a master's degree after graduation. After coming out, he once cooperated technically with the German MBB company MPC-75 project. In 1992, he became the deputy director of the 603 Research Institute. Now he has become the full director. He is Mr. Chen's close assistant and has also contributed a lot to the research and development of the Flying Leopard fighter-bomber.
Mr. Chen trained him as his successor. Next, the Air Force will start a large aircraft project. He hopes that Tang Changhong can take a leading role in this project and be the leader. In this case, Tang Changhong will also become the youngest aircraft in the country. Chief Division.
Tang Changhong is not tall and slightly fat, with a calm smile on his face.
“I heard that you have conducted preliminary research. What results have you produced in the past few years?” Qin Tao asked.
"One of the most important research and development results is the supercritical airfoil." Tang Changhong said: "We are currently pre-researching this airfoil. After the official project is approved, we will blow all our pre-research results into the wind tunnel and make decisions from them. The best choice comes.”
There is a big difference between military transport aircraft and civil aviation passenger aircraft. The most important indicator of civil aviation passenger aircraft is fuel efficiency. For civil aviation enterprises, fuel saving means saving money. Next is the number of crew members. If you can use a two-person crew instead of a three-person crew, you can save the cost of one crew member.
For military transport aircraft, fuel economy is the second priority. After all, the military is not afraid of consuming fuel. Their aircraft must first ensure a large load capacity and a long range, and the second is flight speed. If you want to increase the speed, you must not only have advanced and powerful engines. , and also need to have suitable wings.
“Supercritical airfoil” was first developed by NASA Langley Research Center in the United States in the 1960s. It was first publicly released in 1974. Aircraft designers from various countries have highly praised this airfoil. The most advanced C-17 transport aircraft in the United States adopts this airfoil. At the same time, civil aviation aircraft such as Boeing and Airbus have also begun to use this airfoil. This airfoil improves the cruise efficiency and economy of the passenger aircraft.
Due to its advanced performance, this supercritical airfoil has even been called two major breakthroughs in aerodynamics in the 20th century, together with the swept wing.
Of course, this kind of airfoil cannot be made based on just a few documents. It must go through a lot of wind tunnel experiments and be combined with the aircraft. The airfoil of the Y-20 has also gone through arduous tests. Made with hard work.
Its upper wing surface is relatively flat, but the lower wing surface has a concave design, and the trailing edge of the wing has a larger and thinner curvature. The benefits of doing so are increased flight speed and reduced weight of the wing structure.
When the flight speed of ordinary airfoil design is close to the speed of sound, shock waves will be generated on the wings, which will increase the resistance of the aircraft. Not only will the amount of shock waves generated by this unique "supercritical airfoil" be smaller, but it will also be located very far back, which can prevent the shock waves from vibrating the fuselage and achieve the purpose of saving fuel.
So, although the Y-20 is similar to the IL-76 in appearance, it is actually quite different. With different wing shapes, it can be classified as two different aircraft.
After hearing Tang Changhong's introduction, Qin Tao nodded: "Yes, we have to be in line with the world's advanced level and make aircraft with our own characteristics. Our future domestic early warning aircraft, aerial tankers, electronic warfare aircraft, etc., all rely on It’s on you!”
“We will definitely go all out!” Tang Changhong said excitedly.
Qin Tao also felt a little emotional. He was obviously not from the Air Force, but what he said made the people present very moved. Of course, he knew the reason. After all, no one would miss the mark in any project he passed. .
Now that he is helping to contact this large aircraft project, everyone is of course very excited, which means that the large aircraft project will be launched soon, and there will definitely be a brilliant future in the end.
"Mr. Qin, regarding engines, the suggestions you put forward by the Air Force are very pertinent." Mr. Chen continued to talk about specific technologies: "At present, our country is still lagging behind in terms of engines. Our Flying Leopard fighter-bombers , relies on the mature Spey engine. Now, it is the right choice for our large aircraft to use Lao Maozi's D-30K engine first."
Hearing Mr. Chen say this, Qin Tao suddenly thought of something: "Mr. Chen, have we completed the full localization of Sibei?"
The localization of SPEI also went through some twists and turns. On December 13, 1975, SPEI's introduction contract was officially signed. The goal at that time was very clear: within 3 years, replicate using British materials, blanks, finished products and accessories. Produce engines of the same quality level as those in the UK; within 5 years, use domestic materials, blanks, finished products and accessories to replicate engines that meet the above requirements.
After entering the 1980s, the first phase of the goal was finally completed, but then it came to an abrupt end.
Since the introduction of Spey, there has been a lot of criticism. This British engine of the 1960s has become outdated. What the country needs is a high-thrust engine and so on.
At the beginning, the Feibao project was only to solve the problem of the inventory of Spey engines. Now, seeing that the Feibao has been finalized and is about to be equipped with troops, the engine is a big problem again. If you can't imitate it in China, you can only go to the UK to buy second-hand Spei!
"Yes, the localization of Sibei is a big problem." Mr. Chen said with emotion: "As our Flying Leopard began to test flight, the problems with the Sibei engine also became prominent, and our brother factory continued to start the process of Sibei's engine. The localization plan uses our own domestically produced blanks to manufacture domestically produced turbofan nine engines. Last year, this engine passed a 150-hour endurance test, with a localization rate of 70%."
Qin Tao couldn't help but shake his head: "This is still far from enough!"
Even if the localization rate is 99%, it may be stuck by the remaining 1%, let alone the current localization rate of only 70%! When he was working on naval gas turbines, Qin Tao had met the technical staff of Factory 430 and told them that there was a demand for at least 500 engines of this kind, and localization was a must!
Who would have thought, but it still doesn’t work.
"At present, we have been able to stably produce WS-15 engines." Qin Tao thought of something and continued: "We have reached the world's advanced level in many engine processes, and the remaining 30% of parts are If we can’t figure out the original craftsmanship of the British, can we use our existing craftsmanship to make it?”
"Yes, Mr. Qin, your proposal is very good. We will report it to Factory 430." Mr. Chen fully agreed with Qin Tao's suggestion.
Spey is a British technology from the 1960s, and the turbofan-15 is Lao Maozi's technology from the 1980s. This kind of replacement by our own side should not cause any big problems, and it can even make the performance of the Spey more advanced.
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(End of this chapter)