Once upon a time, two young people got together, determined to build an advanced aero engine.

The first young man said: "I plan to start from scratch, learn from other people's works first, and start with models with low material and process requirements and simple structure. Then figure out bit by bit how each part of this thing works and how it works. By trying to modify their designs little by little, find the rules in them, and summarize a set of theories by yourself. In the end, according to their own material and process level, they can make the most reliable and best performance model within their ability. ”

The second young man spoke, "Well, there's no need to start from scratch. Let's copy this thing first, it's pretty simple, it's broken? Forget it, we don't want this, let's copy the next one. "I copied a few engines, and found that there was nothing difficult, we made a very advanced one, three streets stronger than foreign countries, I rely on it, but we can't do it with such a lot of effort? Forget it, we can't do this, don't do it, buy foreign ones." "These foreign engines are good, what do you want to buy, and they won't be sold abroad? "Damn, it's so hard"

Self-reliance, step by step.

Copycat borrowing, tinkering.

This is the two-legged walk of China's aero engine research.

Two completely different paths.

One is to start from scratch.

One is to start directly from the sky.

For historical reasons, these two legs have always been uneven. One moment left lame, the next lame again.

Sometimes, it's still lame on both legs.

Obviously, on the road of self-improvement in engine development, the first young man is a reasonable role model. Our country needs so many engines that it is absolutely impossible to copy them just by copying them.

Unfortunately, however, the actual situation in our country is closer to second place. In the long history of engine imitation, improvement, self-development and introduction, China's engine has been in a state of doing one and losing one for a long time, failing to systematically summarize the accumulation of technology and experience, and sublimation into a complete theoretical system to guide the research and development of new engines. In this harrowing experience, the turbofan 6 is the most controversial one in the academic world.

Some people even attack it as the biggest cancer, and the damage to this day is unimaginable.

And the military fans of later generations have a seriously polarized attitude towards the dismount of the turbofan 6. Some people are heartbroken, some people are gloating, and some people are relieved.

More people were at a loss, not knowing what was going on.

In the words of Baidu Encyclopedia: "The turbofan 6 aero engine is the first military afterburner turbofan engine with a thrust-to-weight ratio of 6 in China, which was stopped in the early 80s and failed to be put into use, but it is of great significance in the history of China's aviation industry." ”

To quote the words of an in-depth article: "So far, none of the domestic aero engines put into service in China have been completely independently developed in the strict sense. It was developed from a type of blade and a wheel disc, and gradually formed a first-stage compressor rotor and a first-stage turbine. The stage is then gradually expanded to become a basically complete combination of high and low compressor and turbine. Then the core engine that makes up the engine and even the complete gas generator are tested, and finally the type verification machine is derived, and finally perfected into the equipment model, which has never appeared in the public aero engine in China. ”

"The long-term lack of this upstream research has made it impossible for China to form a solid and detailed own theory, test basis and design basis and means in the field of engines. In the process of model development, the developers had to refer to the existing engines of various types, adopt the principle of similarity to scale the design, or even direct mapping and reverse engineering, and patchwork and integrate the various parts of different types of engines in different countries. ”

It is in this context that the turbofan 6, a performance index of 126 tons of thrust, as high as the Taihang engine's finalized index, and the unprecedented difficulty of development, began the preliminary design in October 1964, but there was a miraculous speed at which all the drawings were completed in 1966 and the prototype began to be trial-produced. In this kind of hidden design, the defects of performance matching and coordinated operation between a large number of components are hidden in the lack of materials and processes, and the serious shortage of trial parts and prototypes makes it extremely difficult to eradicate these intertwined faults, and the exhaustion of all means is still not the end of the day. ”

Overall, the turbofan 6 is a big tragedy.

It was launched three times, dismounted three times, and relocated the production base five times. Intermittent, lingering.

Its researchers believe that it was born at an ill-timed time and ill-fated.

Onlookers, on the other hand, believe that from the very beginning, the study of Turbofan 6 was wrong. It's simply a castle in the air, a mirage.

Researchers believe that the failure of turbofan 6 is due to insufficient investment.

And onlookers believe that the turbofan 6 is a complete waste of valuable national resources.

Although forty or fifty years have passed, there is still a debate about the pros and cons of the Turbofan 6. There is always no conclusion.

What is Cheng Kailong going to do?

Take yourself to see the wreckage of the Turbofan 6?

"Your guess is right. Our tech team is also very polarized. Cheng Kailong said bluntly, "Some people advocate starting from scratch and coming step by step." Start with a few solid products. It doesn't matter if the indicators are smaller. But more people come up to make a big thrust, and they are the first in the world in various indicators. ”

"I'm afraid the latter has the upper hand, right?" Wang Buan sneered disdainfully.

"That's true. Cheng Kailong did not shy away from saying, "The current exaggerated style is also a bit powerful." ”

"It's easy to catch up with the United States!"

"But it's not all that rosy. ”

"Ella's third uncle. ”

"Huh. ”

Cheng Kailong smiled slightly bitterly.

Of course, he understood what Wang Bu'an meant.

Ella's third aunt is the homonym of the polar bear "31" engine. It is the latest engine to be introduced in our country.

On the one hand, it is overwhelming propaganda that domestic aero engines have broken through the level of something. It feels very powerful. It seems that the US imperialist can be beaten at any time. But on the other hand, it is necessary to purchase advanced engines from foreign countries. Anyone with a discerning eye can see that there is a problem here. Of course, the details of the specific inside story are not good.

Some researchers have already become old fritters.

Sleek and sophisticated, deceitful.

Whether the Taihang engine is good or not? There have been many debates. Some people's views are still very intense.

In Wang Buan's view, Taihang has made great progress. But there are also shortcomings.

Because the Taihang engine was developed on the basis of the turbofan 6. With some usual faults.

There is certainly some exaggeration in the propaganda.

There is certainly some falsification in the data.

The real performance, only the troops themselves know best.

After the Taihang engine was equipped with fighter jets, it was stopped in the air twice, and the harm was extremely serious.

As for what engine parts flew out of it, Wang Buan would like to believe that it was the enemy's slander. Otherwise, its designers would definitely have to be dragged out to shoot targets. It's too careless for human life.

"It's here. ”

"Get out of the car. ”

Cheng Kailong took Wang Bu'an to its industrial park.

From a distance, Wang Bu'an saw a large aero engine placed outside the industrial park.

Its exterior was rusty, crumbling, and dilapidated.

However, its basic size is still intact.

This is the turbofan 6 aero engine.

An unavoidable topic.

A thing that is debated.

Wang Buan silently walked to the side of the turbofan 6.

Its wreckage is still relatively intact.

After all, it was never officially installed on an active aircraft. There is no possibility of being destroyed.

However, the parts inside it were also very badly damaged.

This is the result of trial and error.

In particular, the life test is very devastating for the engine.

He reached out and touched the metal wreckage.

Robot Elf One automatically analyzes the composition of metals.

The shell is an ordinary iron-based alloy and can withstand a temperature of about 760 degrees. Apparently there is nothing wrong with that.

The shell of the engine generally does not have too high temperatures.

The inner wall is mainly a nickel-based alloy. Withstands a temperature of about 1200 degrees. There is something wrong with this one.

Once the speed of the turbine is extremely high, the temperature of the inner wall is definitely more than 1200 degrees. Under normal circumstances, it will reach or even exceed 1500 degrees.

Obviously, there is a 300-degree gap in the middle.

This gap is very fatal. At any time, it can cause extremely serious problems with the engine. It's very difficult to pass the test.

The main thing is the turbine blades. It's also a nickel-based alloy.

Obviously, this is the most fatal flaw.

Because the maximum temperature of nickel-based alloys is about 1200 degrees.

Turbine blades need to withstand temperatures of more than 1,500 degrees.

More critically, the strength of nickel-based alloys cannot be used to make turbine blades.

Turbine blades are subjected not only to very high temperatures, but also to very high pressures, as well as extremely terrifying centrifugal forces.

Nickel-based alloys can't even reach the first point, and the next two points are even more difficult.

According to the estimation of the quality of the turbine blades of this turbofan 6, it will run for about 10 hours at most, and then the turbine blades will have to be scrapped.

10 hours, apparently worthless.

Could it be that a fighter jet flies for an average of 10 hours and has to dismantle the engine for overhaul?

I'm afraid the Air Force Rabbit is going to shoot you.

There is no doubt that cobalt-based alloys have the best properties. It can withstand high temperatures of more than 1500 degrees.

The problem is that our country is a country with very poor cobalt resources.

The technical difficulty of manufacturing cobalt-based alloys is also very large.

On the wreckage of turbofan 6, Wang Buan did not find any cobalt resources.

It is not known whether the properties of cobalt have not been discovered at all, or whether the cobalt-based alloys at that time were not yet noticed.

It can be inferred from this that the history of this turbofan 6 should be very long.

Such a backward engine is now rare.

In today's aero engines, the proportion of nickel-cobalt alloy is getting heavier and heavier. The proportion of titanium alloy is also getting higher and higher.

Only nickel-cobalt alloys can withstand extreme temperatures. Titanium alloy is to reduce weight.

As for the turbine blades, they are all monocrystalline blades.

Using nickel-based alloys for turbine blades, it's no wonder that there are rumors that parts of the engine fly out.

Really, not surprising at all.

Once the turbine blades fall off or break, anything can happen.

In the final analysis, it is a question of raw materials.

The level of raw materials is not enough, and even the best design is difficult to achieve.

On the other hand, if the quality of the raw materials is good enough, then even if there are some flaws in the design, it can still burst into amazing power.

"Which garbage heap did you turn out of?" asked Wang Bu'an casually.

"This is what I pulled out of an abandoned warehouse at Yanzhou Airport. Cheng Kailong said, "I gave it to you." ”

"What did you give it to me?" Wang Buan shook his head and said, "It's not worth much." ”

"If you can make a copy of one, you can gag a lot of people. ”

"What do you mean?"

"According to its design specifications, make a usable turbofan 6 without major problems. ”

"Why?"

"Prove what you're capable of. proves that you Wang Buan is not idle, flamboyant, traitorous, and rebellious. ”

Cheng Kailong said solemnly.

He's not kidding. He really hoped that Wang Buan would be able to do it.

At the beginning, the design of the turbofan 6 was so ambitious and joyful. With the technical conditions at that time, it was completely unattainable. Today, however, it is outdated.

The high-thrust engines in today's world are often more than 14 tons or 15 tons. The largest even reached more than 18 tons.

There is even information that the 135 engine of the US imperialism has undergone a major upgrade and has also passed ground tests, with a thrust of more than 23 tons.

And the design of the turbofan 6, only less than 13 tons. Obviously, it can't keep up with the times.

However, this is definitely not to say that it is useless.

On the contrary, it has many more uses.

You know, there are still a lot of less advanced aircraft in our country.

If the reliable quality turbofan 6 can be replaced, the performance of these aircraft can also be greatly improved.

For example, J-6, J-7, J-8 or something. There are also various trainers.

The key is to be reliable in quality and low in cost.

"Full replication is not possible. Wang Buan shook his head and said.

"Why?" Cheng Kailong was a little disappointed.

"Because, such a backward product, I don't want to copy it. ”

"What do you mean?"

"With the same design, with a few modifications, it can reach a thrust of about 18 tons. ”

"Seriously?"

Cheng Kailong immediately extinguished the cigarette in his hand excitedly.

Turbofan 6 capable of reaching a thrust of 18 tons?

How can it be?

Is Wang Buan serious?

He's not just talking nonsense and deliberately exaggerating the data, right?

"You don't have to doubt it. Raising the thrust to 18 tons, it is not a big problem. Wang Buan said methodically, "You should remember how the turbofan 6 passed the test at the beginning." ”

"Of course I do. Increase the combustion chamber temperature. It has been increased by more than 50 degrees. Cheng Kailong said stupidly.

"That's right. It is to forcibly raise the temperature by 50 degrees. ”

"But the consequences are devastating. ”

"Yes. ”

How serious are the consequences?

As a result, the overall life of the engine has decreased significantly. The overhaul took less than 150 hours.

In other words, an engine needs to be replaced in a maximum of 150 hours.

As a result, there is a buy-one-get-one-free phenomenon.

Why?

There must be 10 more on the shelves. Maybe 13 will have more. Thank you all for your support.