Galactic Tech Empire

Chapter 247 Engine

More than half an hour later, the test results of the experimental samples came out.

"Li Suo, there is no change."

"Continue to increase the stress test." Li Xiang was not discouraged, after all, scientific experiments cannot be completed overnight.

The experiments in the laboratory continued, while Huang Haojie was thinking about something.

The sizzling sound filled the entire laboratory. As the pressure increased, the noise generated became louder and louder. People in the laboratory had to wear earplugs.

After more than three hours.

"Good news for Li, the solid-state maintenance temperature of submetallic oxygen has increased."

"How much has it improved?"

"Raised to minus 41 degrees Celsius."

"How long can it be stored beyond the temperature?" Huang Haojie asked another question.

"It can be kept for about 41 minutes at a temperature above minus 22 degrees Celsius and below 16 degrees Celsius." The researcher replied with a look of admiration.

Their research institute has been working for several months without a clue, but Huang Haojie broke the deadlock as soon as he came, and had to make them worship.

"Increasing the pressure, I have a hunch that success is waving to us." Li Xiang ordered.

"Ok."

The lab is busy again.

Looking at their experiment situation, Huang Haojie might not be able to complete it for a while, so he beckoned to Li Xiang.

He typed on the display screen of the holographic bracelet: [You guys are busy first, I will go to another research institute to check, and send me the Panda account if there are any results. ]
Li Xiang made an OK gesture.

……

Leaving the noise-filled Materials Research Institute, Huang Haojie headed for the Hydrogen-Oxygen Engine Research Institute in an electric car.

Looking out the car window, there are red maples and kapok trees, and another year has passed before I know it.

With the expansion of Yinhe Technology, the scale of each research institute has also expanded. Now the entire Shanmei is either a factory of Yinhe Technology or a research institute.

The hydrogen-oxygen engine research institute he is going to is near Zhelang Town in Red Bay, more than 20 kilometers away from the material research institute.

The hydrogen-oxygen engine research institute of Yinhe Technology was established very late, and it was only established in November last year.

Of course, in the face of the rich and powerful Yinhe Technology, the scientific research force of the Hydrogen-Oxygen Engine Research Institute is already very good, and a large number of researchers from Dongdao have been added to it.

They are now tackling key issues related to hydrogen-oxygen engines.

Huang Haojie was looking at the situation of the hydrogen-oxygen engine research institute.

In fact, the current space agencies or enterprises of various countries have different engine routes.

The engines of space rockets can generally be divided into: solid fuel rockets, liquid oxygen kerosene engines, liquid hydrogen and liquid oxygen engines, liquid oxygen methane engines, and nitrous oxide/hydrazine engines.

The advantage of solid fuel is that it is convenient to store and launch; the disadvantage is that the fuel is expensive and the specific impulse is small (small specific impulse means small load).

The advantages of the liquid oxygen kerosene engine are high cost performance and high specific impulse; the disadvantage is also very obvious, the combustion chamber is easy to sinter, which is not conducive to the repeated use of rocket engines.

The liquid oxygen and liquid hydrogen engine has the advantages of high thrust and high specific impulse; the disadvantage is that the storage of liquid hydrogen is difficult and the production cost is high.

In addition, the low temperature of liquid hydrogen has caused many engineering difficulties. If liquid hydrogen encounters air in the pipeline, the air will freeze directly and block the pipeline.

The density of hydrogen is extremely low, and the molecules are extremely small. Where other gases cannot penetrate because of the small molecules, hydrogen can. Therefore, hydrogen pipeline valves have put forward extremely high requirements for design and manufacture.

At the same time, the hydrogen tank is large, but very light, which is not very friendly to the overall design.

In addition, hydrogen gas can penetrate into metal parts, causing hydrogen embrittlement problems.

As for the dinitrogen tetroxide/hydrazine engine, this is similar to a solid-fuel rocket. Not only is the fuel expensive, but damn, it is poisonous!Known as toxic hair.

Currently the most promising is the liquid oxygen methane engine.

Although the specific impulse of liquid oxygen methane is lower than that of the excellent hydrogen-oxygen combination, it is still higher than that of liquid oxygen kerosene, which makes this fuel-oxidant combination have practical value.

It is relatively difficult to design and manufacture methane fuel tanks. Compared with the combination of hydrogen and oxygen, the boiling point of methane is much higher than that of liquid hydrogen, close to that of liquid oxygen, and its molecules are large.

Therefore, the fuel tank of the liquid oxygen methane rocket is about the same size as the oxygen tank, which saves a lot of trouble.

Most of the design cost and most of the manufacturing cost of a rocket engine is its turbopump.

Because the density of hydrogen is too low, the number of revolutions of the hydrogen pump is high, and the design is very difficult. Multi-stage pumps are required to achieve the desired combustion chamber pressure.

From the fuel tank, to the pipeline, to the turbo pump, the difficulty of the methane rocket has been greatly reduced.Its turbo pump even one stage is enough.

Compared with kerosene rockets, engines with liquid oxygen and methane are less prone to coking.

Not only to increase the temperature of the gas generator, but also the pressure potential of the main combustion chamber is greater.And when it is used again, it saves cleaning work.

Therefore, space agencies or enterprises in various countries are currently developing liquid oxygen methane engines.Blue Origin is working on a liquid oxygen methane engine, and Elon Musk's SpaceX next-generation heavy rocket also chose a liquid oxygen methane combination.

Of course, the hydrogen-oxygen engine is also very competitive.

Also talk about the Saturn V.

Although it has the most powerful engine in history, its principles are not the most advanced.

The combustion chamber pressure of the Saturn V F1 engine is less than 10 MPa (that is, 100 standard atmospheric pressure), which is not conducive to improving performance. The engine chamber pressure of the gas generator cycle is generally low, and the current engine chamber pressure of SPACEX is also less than 10 MPa .

More advanced principles should be adopted for high chamber pressure, such as the staged combustion cycle engine used by Mao Xiong and Dong Tang, the ultimate chamber pressure has reached 25 MPa (250 atmospheres).

At that time, because the research on the principle of kerosene rocket engine was not thorough enough, it was believed that the chamber pressure of kerosene engine could not be increased, so NASA gave up the kerosene staged combustion cycle engine.

The real reason is that there is a problem with the crude oil they use, and the sulfur content in the produced kerosene is too high, which leads to damage to the engine under high chamber pressure.

Due to the low sulfur content of the crude oil produced by the oil field, Mao Xiong easily realized the high chamber pressure kerosene engine, and he will study the principle later without delay.

Therefore, in scientific research, the factor of luck is very large. The marine plankton hundreds of millions of years ago determined the development direction of rocket science later.

Later, NASA turned to recyclable spacecraft and reusable rocket engines in an all-round way in the 70s. In principle, hydrogen and oxygen engines are the most suitable for reusability.

So there was a staged combustion cycle hydrogen-oxygen engine represented by the space shuttle SSME engine.

In order to develop reusable spacecraft, Mao Xiong has also embarked on this road. The RD0120 of the Energy Rocket is a high-thrust hydrogen-oxygen engine of the same level as SSME.

As for why, NASA does not use its own hydrogen-oxygen engine now, but uses Mao Bear's engine.

The main reason is that there is a problem with their technical route. In fact, in a strict sense, it cannot be said to be a problem.

But when they transferred from the kerosene-liquid-oxygen engine to the hydrogen-oxygen engine, the turn was too sharp, which made it difficult to get up and down now.

Commonly known as the stride is too big, to the egg.

For Yinhe Technology, due to the possession of submetallic hydrogen, storage and processing have become very simple.

If the development of submetallic oxygen goes smoothly, it will be even more powerful for hydrogen-oxygen engines.

The problem facing the hydrogen-oxygen engine research institute is mainly the problem of the turbocharger pump.

Only by solving this problem, the hydrogen-oxygen engine that can be recycled can almost be completed.

(End of this chapter)