Rebirth of the 1980s: The Military Industry Empire

How is an aircraft engine manufactured?

This thing is complex if you say it's complex, and simple if you say it's simple. The core of a turbine engine is the blades, so visiting the production line starts with visiting the manufacture of the blades.

Aircraft engine blades are also divided into several types. The front fan does not withstand high temperatures and belongs to the cold end blades. The rear turbine must withstand high temperatures and pressures and belongs to the hot end. For turbofan engines, the outer duct also needs a large fan.

Hooke introduced to everyone: "In order to improve economy, large airliner engines will pursue a large bypass ratio, so the outer fan blades must be as large as possible, and the larger, the greater the centrifugal force of the fan blades, and the higher the process requirements."

The bypass ratio is an important indicator and is unique to turbofan engines. There is a completely autonomous engine inside, which can be understood as a turbojet engine with a shell. The turbojet engine drives a large fan, blowing air from the outside and passing it outside.

The larger the outer fan, the greater the thrust provided by the same engine, and the more fuel-efficient it will be if the same thrust is required.

Fighter engines have small bypass ratios. This value is generally less than 1. After all, if the bypass ratio is large, the windward area will also be large, which can easily cause high-altitude weakness.

The most advanced aero engine is the American F119. This engine is the power of the F22. In order to use it for the F35, the bypass ratio was increased, and the thrust was further increased, but at the same time, the maximum speed of the F35 could not be increased.

The engines used in ordinary transport aircraft in this era also have medium bypass ratios, generally below 4. For example, the D-30K engine used on the Il-76 has a bypass ratio of less than 2.5, so the thrust is insufficient. When the domestic Y-20 was being developed, it was restricted by the thrust of this engine, which prevented the performance of the transport aircraft from being improved.

Looking at the RB211 again, the bypass ratio of this engine is as high as 5! The diameter of the outer fan is about two meters! In this way, the thrust of the engine mainly comes from the outer duct, accounting for three-quarters of the total thrust.

The manufacturing requirements for such a large blade are very high.

"In the initial development, we wanted to use composite materials to manufacture fan blades. We believe that composite materials have many advantages, such as low specific gravity, good vibration resistance and flutter resistance, but we found that fan blades made of this material cannot withstand bird strikes."

Hooke said: "So, we later had to re-manufacture titanium alloy fan blades, which greatly increased our R\u0026D cycle."

This fan blade is a difficult point for the engine. Just this material has experienced difficult choices and caused repeated changes.

"Can this titanium alloy fan blade be made hollow?"

Qin Yang asked casually.

Old Ma found it a little funny. Hollow fan blades are used for cooling, so they are used in turbine blades. How could the fan blades of this engine use a hollow structure?

However, Hooke took it seriously: "If hollow blades are used, the weight can indeed be reduced, but we have not yet found a suitable process."

"If argon gas is used to blow in a furnace at a high temperature of 1,000 degrees, allowing the three titanium alloy plates connected together to expand and then precisely form, with the outside expanding, a hollow will appear inside. What do you think?"

Hooke's eyes widened: "President Qin, didn't you say you don't understand aero engines? The concept you put forward is really ingenious."

Of course, Qin Yang didn't understand, but in later generations, he had read similar technical articles. At that time, he wanted to build a turbofan engine with a bypass ratio of more than 10, which was super fuel-efficient and powerful. The core machine in the middle was mainly used to drive the fan and basically did not output much power. The fan blades used in this engine had a diameter of three or four meters at every turn and used this technology.

At that time, he just read it casually and remembered these things. Now that he said it, the other party was immediately stunned.

"That's right, I really don't understand. I'm just talking casually. Let's go, let's go and see the manufacture of the integral bladed disk."

Manufacturing is carried out in a space filled with argon gas. The workers responsible for welding are like astronauts, fully armed and wearing full sets of equipment to go in. If they cannot breathe air, they will die inside immediately.

The work intensity is very high, so the daily working hours are very short, and entry and exit have to be done through airlocks, which leads to an increase in manufacturing costs.

"This work can be done in our place. You only need to help us train some technicians, and our people can complete this task. We are the most hardworking."

Qin Yang said.

Of course, this is just a saying. Saving costs is secondary. The key is to master the manufacturing process of aero engines in this way.

It is said that the British provide technology, and we provide manpower and funds to jointly establish a joint venture engine factory. Then, the East will quickly master the production process.

Although there are still problems such as blanks that will restrict the production of the East, it is most important to get in touch with the first step first.

Just as Hooke was taking everyone to visit the production line, Kenneth was holding an emergency meeting with others.

"Although the Easterners have introduced our Spey engine technology, they have not mastered the production of this engine so far. Especially, they cannot even manufacture the blanks and need to use our blanks. If we set up the production line there, as long as we do not hand over the blank production technology to them, we can control their production."

One technician said.

"That's right, it is impossible for the Easterners to master the complete set of processes. It doesn't matter even if we let them assemble. As long as they can purchase our engines, with a market of tens of thousands of units, our RB211 can completely open up the airliner market!"

"Anyway, they are paying for it, so what if we let them assemble it?"

The opinions of the people were surprisingly consistent. There was no way, after all, they needed to sell the engine as soon as possible, otherwise they would have to drink the northwest wind!