Galaxy Technology Empire

The turbopump of a space rocket is the only high-speed rotating machine among the important components of the rocket engine. It is called the heart of the liquid rocket engine in the industry.

Its working principle is similar to that of a car's turbocharger. It uses gas to drive the rotation of the turbine to drive the pump to work, pressurize the low-pressure propellant in the rocket tank, and deliver it to the gas generator and thrust chamber in real time for combustion.

Liquid rocket engine turbopumps are designed with great emphasis on light weight and high performance, and many turbopump components are designed close to the limits of technological development.

Therefore, to make the turbopump reliable and adaptable to the requirements of a launch vehicle or spacecraft, many aspects of the problem must be solved.

For example: To meet performance and weight requirements, a turbopump must operate at high speeds, and therefore must have bearings and seals that meet life requirements at high speeds.

In addition, the pump must have a high suction performance inducer to reduce tank pressure and weight.

The aerospace agencies currently developing kerosene-liquid-oxygen staged combustion cycle engines are Dongtang and Maoxiong.

However, there are many types of staged combustion cycle engines. Sunland and Milijia use hydrogen-oxygen engines, and they generally use high-pressure oxygen supplementation.

The core of the rocket is the engine, and the core of the engine is the fuel pump, because the rocket engine itself is just a very simple cavity, and the key issue is how to provide it with enough fuel.

The way fuel is provided is through circulation.

Judging from the current development trend, the cycle methods of rocket engines are roughly: extrusion, expansion, gas turbine, and electric thrust.

Gas turbines can be divided into several types: gas generator, staged combustion, full flow staged combustion, etc.

They all use rocket fuel to drive a small engine, and then drive a turbine pump to pump the fuel out.

The gas generator extracts a portion of the fuel to drive a gas turbine, which then drives a turbine pump to pump more fuel to the main engine.

The exhaust gas generated by the gas turbine is directly discharged from the body. This is the principle of the Merlin engine of the Space Exploration Company. Because the used fuel does not participate in the secondary cycle, it is also called an open cycle.

The more advanced one is the staged combustion cycle. The exhaust gas generated by the gas turbine will enter the main engine together with other fuels and be burned again to avoid waste.

There are two mixing methods of fuel and oxidant supplied to the gas turbine. One is excess fuel, which is fuel-rich combustion; the other is excess oxidant, which is oxygen-rich combustion.

The exhaust gas after oxygen-rich combustion flows into the main engine and requires more fuel, so it is called supplementary combustion.

Even more advanced than the staged combustion cycle is the full-flow staged combustion cycle.

Unlike pumping part of the fuel to drive the turbine, full flow means all the fuel is burned once to drive the turbine, which can provide more powerful turbine power, and the combustion effect is better after mixing in the main engine.

The Raptor engine currently developed by Space Exploration Company is this kind of engine. The fuel is methane, which goes through two pre-combustion chambers of fuel-rich combustion and oxygen-rich combustion, and then meets in the main combustion chamber.

High pressure refers to the performance index of the engine.

Rockets generate thrust through backward jets. What determines the speed of the jets is the pressure inside the engine combustion chamber (chamber pressure). High performance is good if the pressure is high.

And the high chamber pressure means that the turbopump must have enough pressure to send fuel into the engine, so the performance of the turbopump engine will definitely be higher.

The chamber pressure of the YF100 of Dongtang Aerospace System is 18 MPa (1 MPa is equal to 10 standard atmospheres), which is a high pressure. For comparison, the Merlin engine of the Falcon 9 is less than 10 MPa.

However, Milijia’s unique skill is low chamber pressure and high performance. The F1 engine of the Saturn V is a low-pressure gas generator cycle.

Before he knew it, Huang Junjie's electric car had arrived at the entrance of the Hydrogen and Oxygen Engine Research Institute.

Several security personnel rushed over.

"Boss, I'll go and notify Director Qin right away."

"No need, I'll just go in."

The Hydrogen and Oxygen Engine Research Institute is located near mountains and rivers, with more than half of the space located in mountains or underground.

Having heard Huang Haojie coming, director Qin Tongxing came over quickly.

"Boss, welcome to come over and guide us."

"Where is the development progress of the hydrogen-oxygen engine?"

"We are developing a magnetic bearing system."

"Go and have a look."

"plz follow me."

The group of people came to a laboratory where magnetic levitation bearings were being developed.

A huge electric motor is running crazily.

"This motor is an experimental machine we developed using room-temperature superconductors and strong magnetic repulsion materials." Qin Tongxing pointed to the motor and introduced it.

The difference between the turbine system of a space rocket engine and the turbine system of a car is the power source of the turbine.

Automobile turbine systems can be divided into three types according to the power source: exhaust gas turbine, mechanical turbine, and electric turbine.

As the name suggests, the exhaust gas turbine uses the exhaust gas from the exhaust pipe to drive the turbine; the mechanical turbine uses the vehicle's transmission system to drive the turbine; as for the electric turbine, it uses the battery to drive the electric motor, thereby driving the turbocharger.

There are generally two types of turbine systems on aerospace rocket engines.

One is a small engine turbine and the other is an electric motor turbine. The former is more common, while the latter is currently in the research and development stage because it is difficult for the motor to reach a speed of more than 100,000.

What the Hydrogen and Oxygen Engine Research Institute is developing is an electric motor turbine system.

"What's the speed?"

"150,000 revolutions per minute."

Huang Junjie nodded with satisfaction. It was very rare to be able to achieve this speed.

At present, exhaust gas turbines or mechanical turbines can reach 120,000 to 160,000 rpm.

But the maximum number of electric motors is more than 10,000 rpm. This is a DC motor. If it is an AC motor, the maximum number is 3,000 rpm.

Why is the motor speed so low?

Rotor dynamics determines that when the linear speed of the rotor reaches a certain speed (such as 150m/s), the centrifugal stress exceeds the strength of the rotor, causing some parts of the rotor to detach.

This is a common problem faced by all high-speed motors.

Simply put, mechanical strength limits the rotation speed.

In addition, for brushed DC motors, excessive speed will cause serious friction between the commutator and the brushes, and the arc will also increase significantly. The heat accumulated by the two will quickly burn the brushes.

The bearing at the end of the motor also has a certain speed limit, giving the speed a bottleneck.

After all, it is a question of materials.

If the material meets the requirements, theoretically the speed of the DC motor can be close to infinite.

Materials science is exactly the strength of Galaxy Technology, so with the application of various new materials, the motor turbine of the Hydrogen and Oxygen Engine Research Institute can reach a speed of 150,000 rpm.

"I am very pleased that you can achieve this level. I will keep up the good work."

"I will definitely not disappoint the boss and everyone." Qin Tongxing said quickly.

"How high can the chamber pressure of the combustion chamber be now?" Huang Junjie then asked.

"21 to 22 MPa is the limit. We expect to increase the speed of the turbine system to 400,000 to 500,000 rpm, so that the chamber pressure in the combustion chamber can be increased to about 30 MPa."

"Can the combustion chamber withstand a pressure of 30 MPa?"

"No problem, we use nano-stainless steel material, which is not only very strong, but also can withstand extreme high temperatures of 2,700 degrees Celsius. After testing, the combustion chamber of the new material can withstand the ultimate pressure of 59 MPa." Qin Tongxing explained.

"To increase the speed of the motor, you can communicate and cooperate with the Electrical Machinery Research Institute."

"We often communicate and cooperate with them in this regard."

"Um!"

Huang Haojie, accompanied by Qin Tongxing, continued his inspection at the Hydrogen and Oxygen Engine Research Institute.