Technological Supremacy Chapter 458: Coaxial jet injection system!

Luo Jia explained to the general on the phone that the final test of the space program is cost-effectiveness, to see who can deliver goods to space at a lower price.

Russia's RD-171 engine, while creating history in thrust, has also reached a record high in cost, which corresponds to the characteristics of Maozi's great success.

Luo Jia is a man of science and technology, a believer in dataism who pays attention to seeking truth from facts. Under his leadership, Star Technology's rockets are completely designed according to the needs.

Furthermore, Luo Jia has the habit of hiding his hands in everything, and this time is probably no exception. No one can guarantee that there are no amazing secrets hidden in the design of the Xingchen rocket engine.

For Luo Jia, Russia's Yenisei super-heavy rocket has only one function, which is to act as cannon fodder to attract real opponents to this space race, thereby quickly consuming the opponent's strength.

…

Subsidiary of Star Technology, Rocket Lab.

Luo Jia has been in charge of the rocket laboratory for several months, and all plans are advancing at an extremely fast speed. It seems that everything is moving in the right direction, and the only exception is the injection combustion system.

For several days, the Rocket Lab was filled with gloom and mist, and everyone seemed to be under a lot of pressure. Luo Jia's office was filled with whiteboards, with secrets and extremely complicated formulas and numbers written on the whiteboards. .

Except for taking a shower and going to the toilet, Luo Jia almost never leaves the office. He is like a machine running at high speed, working crazily and continuously with high intensity.

His state makes everyone in the lab feel nervous. After all, Luo Jia is the head of the tough guy group. If something goes wrong with him, it will be an irreparable loss for the entire company and even the entire China.

Then everyone discussed and invited Vice President An Ran, hoping that An Ran could persuade Luo Jia, but they were surprised to find that An Ran, like Luo Jia, was also a lunatic!

For forty-eight hours, the two stayed in the office, discussing and analyzing constantly. They are rare geniuses in the world, and their brains are thinking at an extremely fast speed.

Everyone was stunned to hear that An Ran and Luo Jia were arguing in the office. The two were jumping back and forth in different disciplines. They were discussing thermodynamics just now, but they jumped to aerodynamics in the blink of an eye.

In short, it means that it is a waste of the brain. It is okay to follow their thinking for a few minutes. If it exceeds fifteen minutes, the brain will become chaotic. If it exceeds half an hour, the headache will be splitting. crazy.

Since then, the matter has changed from Luo Jia alone, to him and An Ran...

An Ran stayed in the Rocket Lab, and the leaders of the major project teams in the hardware department quit. They complained about the colleagues in the Rocket Lab, why did they ask An Ran to persuade Luo Jia? Anyone who is familiar with Mr. Luo knows that he never listens to persuasion.

In short, the colleagues at Rocket Lab finally realized that there is a reason why Luo Jia and An Ran can stand at the top of the company. They are not only smarter than most people, but also more desperate!

For two bosses to work without sleep, is the injection combustion system really that important to a rocket?

The answer is yes.

As rocket fuel continues to be updated, keeping the injection system stable is becoming more and more difficult.

Not to mention the latest generation of liquid oxygen methane engines, even the previous generation of liquid oxygen and liquid hydrogen engines has also brought huge troubles to scientists. In the future, the requirements for durability and stability will be even higher.

"Next, you continue to improve your ideas. I'm going back. After all, the hardware department is also busy, and I don't have time to stay with you for a long time." An Ran scratched her hair that had already turned into a chicken coop, and said to Luo Jia said.

"Understood, don't just focus on your work, spend more time with your wife and children when you have free time, don't worry about not knowing you as a father in the end." Luo Jia teased.

"Come on." An Ran waved her hand disapprovingly, "You are a bachelor, but you have taught me a lesson on being a father? Let's talk about it when you have a wife and children."

What does this have to do with being single?

He meow's single dog really has no human rights. He said good things, but no one would listen.

Luo Jia shook his head and muttered in his heart.

…

The reason is unclear, and the in-depth discussion with An Ran made Luo Jia change his mind. He wiped all the whiteboards in the office and started from the beginning. Soon, the numbers and formulas on the blank whiteboard were dense again. up.

He is calculating TRinstability, which is Taylor instability. The interface between two fluids with different densities is unstable. In the gravitational field, when the heavier fluid is on top of the lighter fluid, the instability has can happen.

During jet injection of a rocket engine, the acceleration causes cavitation of the propellant in the pipeline, and the bubbles after cavitation will induce compressible Taylor instability.

In addition, when the propellant flows at high speed in the centrifugal pump and pipeline, cavitation will also occur. The bubbles generated by cavitation will release the pressure at the moment of jet injection. Assuming that the centrifugal pump has cavitation in the working state, then But it will be fatal and must be completely eliminated.

In addition to Taylor instability, the rocket injection device must also take into account RMinstability, that is, turbulent flow instability.

Regardless of the tangential velocity gradient or the normal acceleration, disturbance waves will be generated on the fluid interface in essence. A small amount of disturbance waves propagate at supersonic speed and become shock waves. When the fluid interface with initial disturbance is impacted by the moving shock wave, The peaks and troughs of the interface will produce velocity differences and promote the evolution of disturbances, which will eventually cause turbulent flow and bring huge hidden dangers.

In short, the rocket engine is extremely difficult to design, but a low-cost engine with stable performance ~IndoMTL.com~ and can be used repeatedly for a long time, the design difficulty is not a huge problem. But the difficulty is against the sky!

For example, during the fuel injection process of a rocket engine, the atomized medium is regenerated and cooled by the nozzle wall, becomes gas and then ejected from the nozzle. The shock wave will even be superimposed with the interference brought by the expansion wave.

For another example, in free space, the pressure disturbance caused by the shock wave and combustion will diffuse freely into the environment. Refraction occurs, which often leads to unstable high-frequency combustion.

In any case, there are too many factors that can cause instability. The aerospace industry has gathered the most intelligent brains in the world, but disasters still happen one after another. It can be seen that the most difficult thing about rockets is not to make them, but to create them. To truly achieve stability and security, even the most experienced North America and Russia cannot do this.

The numbers and formulas became more and more complicated, and they were gradually simplified in the following days. In the end, there was only a large whiteboard left in the office, on which were written the results obtained by Luo Jia in the past ten days. The name of the result is called.

Coaxial jet injection system!