A big country of aerospace with black technology

"I still like the weather in the South China Sea. It seems to be always so warm."

Geng Bo, who had just returned to the Wenchang Launch Center from his father-in-law's house, pulled his collar and said.

At this time, the north was still covered in silver.

However, the Wenchang Launch Center still looks like a scorching summer.

Geng Bo, who had just gotten off the plane, felt particularly comfortable.

"No wonder everyone wants to go to Hainan in winter."

In the past few years, although Hainan has experienced a real estate bubble, the tourism industry has shown a booming trend.

Especially in winter.

There is an endless stream of people coming from the north to spend the winter.

At least millions of people.

"How was your Spring Festival holiday? Was it going well?" Zhang Xingyang said.

"Hey, don't mention it."

Geng Bo said helplessly:

"Her parents have been complaining in our ears, saying that the family next door who is one year younger than her already has a grandson, and when will they be able to do so."

"I'm so annoyed that I came back so early."

It can be seen that the Spring Festival holiday is not particularly wonderful for some people.

This is the same whether you are married or not.

"If you come back so early, don't even think about resting. You'll be busy during this time."

Zhang Xingyang laughed for a while and then said.

"Is rocket testing about to begin?"

Although Geng Bo did not specify which rocket it was.

But both of them knew which rocket the other was talking about.

In addition to the heavy-duty manned moon landing rocket.

The institute has no other rocket development projects recently.

"Start vibration characteristics experiments next week."

"This is the experimental project plan, take a look at it first."

Zhang Xingyang pulled out a thick booklet from his desk and handed it to the other party.

"Although we have now established some relatively accurate mathematical models, it is still very difficult to perfectly verify the situation of the rocket."

Geng Bo sighed as he began to look through the vibration characteristics test plan in his hand.

Vibration characteristic testing is not particularly common in other fields.

It is only possible to see it on some equipment with very complex overall structural dynamic characteristics.

After all, every experiment almost requires scrapping some parts, and the cost is still very high.

No one wants to spend this money unless necessary.

"The computing power of current supercomputers is still too weak. When it can be improved by several orders of magnitude, it may be able to reach the level of computational verification."

Zhang Xingyang also expressed a lot of his own opinions on this topic.

In fact, as rocket systems become more and more complex, the computational difficulty is also rising.

Even faster than the increase in computer computing power.

"For the longitudinal coupling vibration test caused by the propellant in the closed system of the rocket body and the power device, do we need to directly conduct physical simulation experiments?"

Geng Bo didn't read very slowly, of course because he skipped some less important content.

But he is still very concerned about the propellant longitudinal coupling vibration test.

Because the heavy-lift launch vehicle uses liquid propellant, liquid oxygen kerosene.

And there are a large number of engines with huge thrust.

Therefore, the liquid in the fuel storage tank is very large!

It can even be said that more than half of the rocket's mass comes from fuel.

This causes the fuel to slosh due to various reasons during launch and flight.

Shaking can cause various vibration problems.

This issue will be taken seriously by everyone involved in relevant work.

Because once the vibration problem intensifies, it is likely to lead to very serious problems such as unstable flight, abnormal operation of the propulsion system, decreased control accuracy, etc.

More likely, it will directly lead to the failure of the rocket launch!

“Yes, you also know that the vibration characteristics want to be simulated according to the mathematical model.

Judging from our current technological capabilities, it is simply impossible.

So we can only use the stupidest but most practical method.

Just take out a rocket and do the experiment! "

There is no other way.

If mathematical models could completely replace experiments, then Zhang Xingyang would immediately cancel the rocket experiments.

But the current level of mathematics and computers simply cannot do this.

It is difficult to establish a comprehensive simulation model just because of the interaction between the natural frequency, mode shape, mode slope, damping coefficient, transfer function, etc. of each structural component.

The cost of rocket experiments is huge.

You must know that the cost of a single YF-500 rocket engine alone reaches 8 million.

The overall cost of the rocket is hundreds of millions of yuan.

Although most of the parts can be recycled and reused after the experiment.

But some parts are bound to be damaged in the process.

Therefore, the cost of a single experiment is about 70 to 80 million.

"Right now, no one in the world except us seems to be conducting research on super-thrust rockets."

Geng Bo raised his head, thought for a moment and said.

"If we want to complete this part of the research and development work, we really have no one to draw from and can only rely on ourselves."

In history, few countries have completed launch vehicles with a thrust of more than 1,000 tons.

The only ones that can be counted are Saturn V and Energy.

But now it’s impossible for NASA to make another Saturn V.

They are still stuck on the unfavorable road of space shuttle.

As for the Energy, it was directly forgotten in the Baikonur Space Center.

Therefore, for us, the only way to go is to rely on ourselves.

Wenchang Launch Center is different from other launch centers in China.

In the early stages of construction, there were plans to develop aerospace tourism.

Therefore, Wenchang Launch Center has a kind of group that cannot be seen in other launch centers.

tourists.

Fortunately, the mobile Internet is not particularly developed these days.

Otherwise, there will definitely be many people broadcasting live broadcasts when the rocket is launched.

General rocket vibration characteristics experiments are conducted in vibration towers.

However, their heavy-lift launch vehicles have no way to use vibration towers.

Without him, the heavy-lift launch vehicle is simply too big.

The vibration tower simply won’t fit!

This is also an important reason why this experiment will cost unprecedented money.

On the modified test bed, the heavy-lift rocket is undergoing final inspections.

Although this is just an experiment on rocket vibration characteristics, everyone still treats it as a normal launch.

"The vibrator has been installed and can start working at any time." Geng Bo said.

The purpose of the exciter is to make the rocket components produce the desired vibration, so as to achieve the effect of the simulation experiment.

"Have all positions been installed in place?"

Zhang Xingyang asked, looking at the rocket that was as big as a skyscraper.

"A total of 48 exciters have been installed on the platforms around the rocket."

The heavy-lift launch vehicle is very large, so more exciters are installed.

For ordinary rockets, about thirty or so are completely enough.

"Now that the installation is complete, let's start testing as soon as possible!"

Zhang Xingyang said after taking a look at his watch.

The heavy-lift launch vehicle is not elastically suspended in the air like traditional vibration tests.

Instead, the entire rocket is erected on the oil-gas support system to meet the boundary conditions during rocket flight.

The engineers accompanying the inspection left the rocket platform.

The experiment officially begins.

The exciter still continues to excite vibrations in the structural parts.

At the same time, the huge liquid filling system also started working.

Tons of liquid are expelled from the rocket's fuel tank every second.

This is to simulate the changes in the propellant inventory inside the rocket at different times during the rocket flight.

Various measuring equipment began to continuously collect data from the rocket.

And aggregate the data into the control room.

The first thing to do is the vibration characteristics experiment, which is to determine the vibration characteristics of the rocket itself.

What followed was the rocket's adaptability to the vibration environment, also known as the vibration environment experiment.

Neither experiment itself was very long.

After all, it only takes a few minutes for the rocket to complete its work.

Generally speaking, the working time of a first-stage rocket is just over a hundred seconds.

However, it still took nearly a week to analyze the generated data.

"Reports on vibration characteristics experiments and environmental experiments are out."

Geng Bo quickly walked into the office and handed the two reports that still smelled of ink to Zhang Xingyang.

Zhang Xingyang did not read the report directly, pointed to his computer screen and said:

"I've already read the electronic report."

"There shouldn't be anything different, right?"

Because he was worried that they would find something different later, Zhang Xingyang said something next.

"The electronic version is the same."

Geng Bo first answered the question, and then said with some emotion:

"The vibration characteristics of the heavy-lift launch vehicle seem to be different from all our previous rockets."

"This is also an inevitable result. Both the engine thrust and the structure of the heavy-lift launch vehicle will be much larger than before."

Zhang Xingyang said affirmatively:

"This result is not too different from what I predicted before. Except for the slight deviation in the vibration amplitude of the shell, it is basically the same."

Geng Bo smiled and said:

"Even if there is a deviation, for us, such an error is still within the allowable range."

Since Zhang Xingyang had already read the electronic report, Geng Bo didn't tell him more about the report.

Instead, he asked about the next experimental plan for the heavy-lift launch vehicle.

"When will the next experimental plan start?"

Before the rocket can actually conduct flight experiments, there are many experiments that need to be carried out.

Including vibration characteristics experiments, ground testing, transportation experiments, wind load tests, docking and coordination experiments, flight experiments, etc.

Follow the general experimental procedure.

The next experiment that should be conducted should be ground testing.

The ground test is the only experiment where the rocket engine is actually ignited after the rocket is assembled.

It can be regarded as the last test of the propulsion system on the ground.

After this, the inspection of the propulsion system will be carried out in the sky.

"The test bench is almost ready and the final equipment debugging is in progress." Zhang Xingyang said after flipping through the work log on the table.

"If nothing unexpected happens, ground testing will be possible next Tuesday."

Compared with vibration testing, ground testing consumes more money.

Although the vibration test also simulated the process of rocket fuel flowing out.

But after all, no fuel is actually consumed.

Ground testing requires the actual burning of hundreds of tons of liquid oxygen and kerosene.

For this ground test, the institute purchased at least 1,000 tons of rocket kerosene and liquid oxygen.

Although the kerosene production base in Yulin is now able to produce high-quality rocket kerosene.

But the price is still relatively high.

Just for these fuels, the institute spent tens of millions.

How strong can a thrust of more than six thousand tons be?

Let's put it this way, if this force is used to push a small hill, it can push it!

This is truly a force comparable to destroying mountains.

The power of immortals in ancient myths is nothing more than that.

On the test platform, the rocket itself, which is more than 100 meters high, is like a hill.

The floor of the test bench has been specially reinforced.

It is difficult for ordinary ground to withstand the ravages of such high temperature and high pressure gas.

Common construction cement grades are mostly C30 or C40.

The cement number of the test bench is C120.

It is enough to withstand the attack of high-explosive bombs head-on, and even armor-piercing bombs are very difficult to penetrate.

This is the only solid ground.

Only then can it support the huge power of the rocket.

"Heavy-lift launch vehicle, first ground test, begins!"

Zhang Xingyang gave an order.

At the bottom of the rocket, after the TNT exploded, a large amount of liquid oxygen and kerosene ignited in the combustion chamber.

Release a massive amount of high-heat gas!

Render the ground a golden color.

Then with the rapidly rising thrust, it gradually turned into light blue.

The flame passes through the diversion trough around the test bench and is directed to the side.

Create a fire dragon tens of meters long.

Accompanied by a large amount of white smoke, it looks like a dragon swimming in it.

The most shocking and powerful thing.

Or the earthquake feeling when the rocket started up.

The experimental control center is not very close to the rocket test bed.

About a few hundred meters.

But even at such a long distance.

Everyone can still feel the vibration of the earth in the control center!

"Good guy, it feels like there are shells exploding in the distance."

Even Geng Bo couldn't help but sigh at the intensity of the shock.

The rocket test run is not very long.

But within these few hundred seconds.

All the liquid oxygen kerosene in the 12 large fuel storage tanks was consumed.

More than two thousand tons in total!

It can be seen that such a big guy.

It’s not just the thrust that’s scary.

The consumption is also very alarming.

After the test drive was completed, Zhang Xingyang couldn't help but said:

"When everyone buys a car, they like to say that XX car is a gas guzzler."

"I still know too little."

"We big guys are the real oil tigers!"

"The amount of fuel consumed by one launch is estimated to be enough to drive thousands of vehicles for a year!" (End of Chapter)