Dreaming back to 1949, the great powers were there to deceive us

At Tongan Machinery Factory, Hu Zhenhua continued to visit the next project. He stood in front of a prototype axial-flow turbojet engine.

This is the mainstream of future engines.

The axial-flow turbojet engine consists of a stator and a rotor. It compresses the air in front into the combustion chamber and ignites it through multiple turbine blades.

This internal structure is complex, but advanced and practical.

The F86 Sabre, the first U.S. jet fighter, uses this type of engine.

But at this time, there is another mainstream engine in the world: the centrifugal turbojet engine.

This engine compresses the gas by using centrifugal force to throw the gas in all directions. The high-pressure gas flows into the combustion chamber at high speed after compression, mixes with the fuel, burns, and is then ejected from the nozzle.

It's like the drum of a washing machine, throwing water around.

It’s just that centrifugal turbojet engines throw out air.

Its advantages are mainly reflected in its simple structure and relatively low technical requirements.

The typical representative of this engine is the MiG-15.

We often say, whether it's a mule or a horse, take it out for a walk.

The quality of an engine usually needs to be tested in practice.

In the skies of the future, two fighter jets with different engines will clash for the first time over the Korean Peninsula! Both will perform impressively.

However, the potential of centrifugal turbojet engines is limited, specifically: the unit frontal area is large, the efficiency, compression ratio and flow capacity are not as good as axial compressors, and the thrust is limited. Therefore, after the 20s, large and medium-sized engines no longer use centrifugal compressors. Only small turbopropeller and turboshaft engines use centrifugal or axial and centrifugal combination compressors.

In its early stages, my country's aviation industry learned from the polar bear and initially adopted centrifugal turbojet engines. However, because it took the wrong path, it wasted 10 precious years. It was not until the late 50s that it developed the first axial-flow turbojet engine.

In the industrial field, it is almost impossible to overtake others.

Because any technological breakthrough is based on a lot of trial and error.

Hu Zhenhua's gaze continued to stay on the engine.

In fact, no matter what type of engine it is, there are three simple steps: compressed air, combustion, and jet!

Air is first drawn into the engine through the intake, where it passes through a compressor, compressing it to high pressure. This compressed air then enters the combustion chamber, where it mixes with the injected fuel and ignites, producing high-temperature, high-pressure gases. This increases the pressure in the combustion chamber and expands. The high-temperature, high-pressure gases are then ejected through the nozzle, generating rearward thrust. The velocity and volume of the jets depend on the engine design and operating conditions.

Hu Zhenhua pondered for a long time, then suddenly walked to the drawing table and began to draw seriously.

Strictly speaking, what Lao Hu draws can only be considered cartoons.

The engine is such a rigorous work of art, how could a poor student like Hu Zhenhua understand it?

Not to mention that he just watched some short videos, even if he was given a blueprint to copy, he might make mistakes.

In half an hour, he drew a total of four pictures, representing the four variants of turbojet engines, namely: turbofan, turbojet, turboprop, and turboshaft!

Hu Zhenhua pointed to the turbofan engine and said,

"Dr. Chen, from your professional perspective, what are the characteristics of this engine?"

Chen Yu, head of turbojet engines, returned overseas PhD.

After looking carefully for a while, he said,

"What's the purpose of this fan in front of the engine? Is it a combination of centrifugal and axial flow engines?"

Hu Zhenhua nodded.

"The most notable feature of this engine is that it has two ducts. Part of the airflow inhaled by the fan is sent to the compressor like a normal jet engine (the term is called the "inner duct"), while the other part is directly discharged from the outer periphery of the turbojet engine casing (the "outer duct"). Therefore, the gas energy of the turbofan engine is distributed to the fan and the tail nozzle."

After saying this, Hu Zhenhua paused. He wanted to see Chen Yu's ability to understand.

After a long time, Chen Yu suddenly said,

"In other words, part of the energy generated by combustion is ejected to generate thrust, while the other part is converted into kinetic energy of the fan. The fan, in turn, compresses the air in the duct, and after it is ejected through the duct, it generates new thrust!"

Hu Zhenhua gave a thumbs up and praised,

"It's true that every profession has its specializations. I admire you! The airflow from the duct is relatively low in speed, enveloping the high-temperature airflow from the core engine, which can significantly reduce noise. Moreover, the airflow from the duct can also cool the core engine."

Hu Zhenhua looked at Chen Yu and continued,

"There's a metric here called the bypass ratio, which is the ratio of the mass of air drawn in by the outer bypass to the mass of air drawn in by the inner bypass! Turbofan engines with high bypass ratios consume less fuel, yet have thrust comparable to turbojets, and they're much quieter."

Chen Yu was silent for a while, then suddenly said,

"This engine is too big. I'm afraid it's not suitable for use in fighter jets."

After a brief thought, Jiang Yunhai said,

"Is it designed for bombers?"

Hu Zhenhua nodded.

"That's right, turbofan engines are usually used in passenger or transport aircraft. Gentlemen, our future aviation needs a new generation of passenger aircraft. I wonder if you can surprise me?"

Chen Yu immediately waved his hand.

"Chairman, we only research engines. If you want to build a complete machine, it's best to recruit a separate team!"

Although Hu Zhenhua was slightly disappointed, he did not force it.

If Chen Yu could conquer the heart of the plane, he would definitely be the first contributor to the passenger plane.

"Dr. Chen, just focus on your engine research. If you need anything, the head office will fully support you!"

Chen Yu was not polite and immediately said,

"Talent, we are in urgent need of talent, especially talent in materials!"

The temperature of the engine combustion chamber is usually as high as one or two thousand degrees, which places extremely high demands on materials!

Hu Zhenhua nodded and shouted,

"Okay, I'll find a way. If you have someone suitable, you can write to them. I'm willing to pay double my salary!"

Chen Yu was overjoyed and immediately said,

"I'll write to a few classmates right away. Not to mention doubling the salary, even if it's the same treatment, they will come without hesitation!"

These are definitely patriotic returnees.

In the era when the country was poor and weak, many overseas students studied abroad at their own expense. When they received the call from the country, they would return home immediately.

But in peacetime, the country has invested huge manpower and material resources in training, but many people are unwilling to come back once they leave.

This is undoubtedly a great irony.

Hu Zhenhua thought about it and said firmly,

"We welcome the return of overseas students, but their treatment will definitely not be reduced. The best housing and the highest salaries will be given to our R&D personnel. TA's implementation of the principle of prioritization is not just talk. If there is only one piece of meat left in Tongan, only the R&D personnel will be qualified to eat it!"

Hu Zhenhua looked at the engineers around him and shouted,

"Starting today, your salaries will be doubled! In addition to the remuneration, I'll also implement equity incentives. For any R&D team's achievements that are commercialized, our equity and profits will be distributed in a 4:3:3 ratio: 4% to the R&D team, 3% to the machinery factory, and 3% to the head office. In the future, the first billionaires will be our R&D staff!"

The engineers around cheered.

Hu Zhenhua looked at Chen Yu with a smile and continued,

"Dr. Chen, you can disclose our salary. We welcome returnees from overseas, but we also want to attract Western talent. But please keep it confidential. Our engines are absolutely cutting-edge in design, so don't let anyone know."

"Ok!"

Chen Yu lowered his head and thought for a moment, then said,

"I think we should open a branch in the United States and build a laboratory there, with our R&D headquarters located in an industrial zone. Once we recruit talented people, internal mobility will be much easier!"

Hu Zhenhua's eyes lit up.

No matter how high the salary offered in the industrial zone is, it is still a remote and poor place in the eyes of Westerners, and they may not be willing to come here.

This is the same principle as working in later generations.

In a big city, you may be able to earn 6000 yuan a month, but if you can earn 3 or 4 yuan a month in your hometown, many people will choose to stay in their hometown.

Why?

Because people are looked down upon when they leave their hometown.

Once you leave your hometown, almost all of your social relationships will be cut off.

In big cities, you cannot enjoy many benefits. For example, the problem of children's schooling is difficult to solve.

There are also a series of problems such as high rent and high consumption.

Suddenly, a flash of inspiration came into Hu Zhenhua's mind.

For some talented people, salary alone is not enough, because they dream of changing the world.

You must give them an excuse they can’t refuse!

What's the gimmick?

satellite!

Yes, this is the project!

Our journey is to the sea of ​​stars!

This plan is called the "Star Project".

No matter whether it can be done or not, let’s start the project first, and fool ~ uh ~ attract a group of talents first!

Hu Zhenhua regained his composure, looked at Jiang Yunhai, and said,

"Dr. Jiang, our machinery factory is classified as a confidential unit. I will assign you security forces. Here, I grant you full authority. With the exception of me and Mr. Guo, you have the right to refuse anyone from entering or leaving the factory! Also, it is best to isolate each project team!"

"Okay, I'll arrange it according to your requirements."

Hu Zhenhua thought for a moment and continued,

"The engine project is classified as top secret, Dr. Chen. I'll allocate a separate area for you!"

Chen Yu was overjoyed and shouted,

"That's the best! Sometimes when friends come to visit, I feel embarrassed to refuse them."

After discussing this issue, Hu Zhenhua pointed to the turboprop engine and said,

"There's not much to say about this engine. Its core is still a turbojet engine, but in order to recover more power from the exhaust gas to drive the propeller, the turbine end of the engine has a higher number of fan blades. This engine is mainly used in medium and low-speed aircraft."

For example, the C130 Hercules transport aircraft used by the US military in later generations uses a turboprop engine.

For example, Tu-95 and Tu-114.

Hu Zhenhua paused and looked at the turboshaft engine again.

"This engine is mainly used in helicopters. Do you know helicopters?"

Chen Yu is a practitioner in the aviation field and of course knows about helicopters.

The world's first helicopter was the VS-1939, which was successfully developed in 300.

"Chairman, now that we've covered the other three engines, could you please give us some pointers on the turbojet engine? This is the highlight of our research and development!"

Hu Zhenhua laughed out loud after hearing this.

"I can't guide you in this area. At most, I can offer some suggestions, but whether they work or not is up to you to verify."

Chen Yu pointed at the picture drawn by Hu Zhenhua and said,

"Chairman, what is this area used for?"

The location he was pointing to was the afterburner.

The world's first use of afterburner on a jet engine was in the mid-1950s.

Hu Zhenhua looked at the drawings and smiled.

"See this spot? It's the fuel nozzle!"

Chen Yu frowned deeply and said immediately,

"After the air has been burned, there is very little oxygen left. If we inject fuel at this time, it will only cause incomplete combustion. What a waste!"

Suddenly, he shouted,

"No, waste makes sense! No matter how little oxygen is left, there's still some!"

Chen Yu suddenly jumped up and shouted,

"I see. This is for acceleration. If an enemy plane attacks, I can speed up and escape in an instant!"

Hu Zhenhua was very satisfied with Chen Yu's reaction and said with a smile,

"Dr. Chen, practice is the only criterion for testing truth. You just said that after combustion, there is very little oxygen left. I disagree with this. After all, the air in the engine is highly compressed. How can it possibly be completely burned? And the front end is constantly providing high-speed airflow!"

"How can this be!"

Chen Yu stared at the blueprint and shouted,

"If the oxygen is not completely burned, then the engine design is unreasonable!"

Hu Zhenhua immediately retorted,

"If the fuel isn't fully burned, it means the design is wrong. In the design, we would rather have excess oxygen than excess fuel!"

Chen Yu jumped up and shouted,

"That's a fallacy! The inhaled air needs to be compressed, which consumes energy. If it can't be used up, isn't it a waste?"

Hu Zhenhua was stunned.

He thought about it and realized that this was indeed the case!

The principle of a turbojet engine is to use combustion expansion and jet power to propel the aircraft into flight, but at the same time, it also recovers energy from the exhaust gas to drive the turbine to rotate and compress the air.

Lao Hu thought for a long time and asked,

"Dr. Chen, have you ever calculated the amount of air you inhale and consume?"

"Calculated!"

"What conclusion?"

Jiang Yunhai suddenly asked,

"Old Chen, there are differences between theory and practice. For example, the combustion time is insufficient, the space is too small, and the oil and gas are not mixed evenly. Have you considered these factors?"

Chen Yu immediately replied,

“These are the basic elements, how could we not consider them!”

As soon as he said this, even he was stunned.

With so many restrictive factors, how could oxygen be exhausted!

But there shouldn't be a lot left, right?

Hu Zhenhua saw Chen Yu's dilemma and said with a smile,

"Doctor Chen, once the prototype is complete, you can extract some of the exhaust gas for analysis! This is no better than just wishful thinking!"

Chen Yu's brows finally relaxed.

"That's exactly the truth!"

He pointed to the tail nozzle on the drawing and asked,

"Is the nozzle diameter adjustable?"

Reducing the nozzle size can significantly increase thrust.

Because the fluid will significantly increase its speed when the pipe narrows.

This is easy to understand. You can try blowing air through your mouth. Is it stronger when you open your mouth wide or when you close it?

The high-pressure water guns used by fire departments also work on this principle.

Hu Zhenhua nodded.

"Not only is the size adjustable, but in the future, we can even adjust the direction of the tail nozzle to enable the fighter to take off and land vertically."

This statement flashed through Chen Yu's mind like a flash of lightning.

Some ideas are obviously very simple, but you just can’t think of them until they appear!

Can jet aircraft take off and land vertically?

What he had not dared to think about before, after Hu Zhenhua proposed to turn the nozzle, made Chen Yu realize that this possibility existed. He took a deep breath and said,

"Chairman, the complexity of this project is probably beyond imagination!"

"That's right. So, there's no need to jump in blindly. Your mission is still to research turbojets. That's the core!"

"Yes Yes Yes!"

People who work in technology are all very arrogant, but in front of Lao Hu, Chen Yu becomes cautious.

Jiang Yunhai looked at the pale sky outside and smiled.

“This night really opened my eyes!”

Other engineers also started talking and flattering Hu Zhenhua.

Lao Hu waved his hand.

"Everyone, I'm only responsible for imagining things. Whether it can become a reality depends on you!"

“All great inventions begin with wild imagination!”

"Hahahahaha!"

A group of engineers laughed happily.

Suddenly, a middle-aged man in his forties grabbed Hu Zhenhua's arm and said anxiously,

"Chairman, you've provided guidance on machine tools, motors, and engines. Isn't it time for you to provide guidance on hydraulic presses?"

……