Into Unscientific

"."

In classrooms.

Looking at Luo Shijun with a serious expression.

Fifth Master Qian's complexion didn't change much, but a bad premonition faintly appeared in his heart.

Luo Shijun was a personal disciple he brought with him when he was at Caltech, and he received a doctorate from Caltech as early as 1950.

Even if you look at the aerodynamic field across the country.

Luo Shijun can also be regarded as a top aerodynamic expert, and is even regarded by Qian Wushi as his successor.

If not.

Fifth Master Qian will not let Luo Shijun be the leader of the theory team anymore.

To know.

In the entire theoretical group, there are still one or two seniors with higher qualifications than Luo Shijun, such as the deputy group leader Chai Zhi.

Let Luo Shijun be the team leader, which is enough to show his ability.

And right now, Luo Shijun can tell the problematic power link, which is equivalent to a person encountering a problem in the field he is most proficient in.

Think here.

Fifth Division Qian immediately took the report in Luo Shijun's hand and read it carefully.

"."

After about five or six minutes.

Only then did Fifth Master Qian put down the report thoughtfully.

He first slowly looked around the scene, and finally put his gaze back on Luo Shijun, and asked his disciple:

"Shi Jun, that is to say, if we want to have a missile with the parameters we need, the body length must be between 90 and 100 centimeters?"

Luo Shijun nodded heavily:

"Yes, teacher."

See this situation.

Xu Yun on the side didn't need an explanation from Fifth Master Qian, and immediately understood what Luo Shijun said about the power link.

I see

It was mentioned earlier.

Due to the limitations of the airship's carrying capacity and stagnant height, the missiles carried by the "Jade Sword Array" cannot exceed two meters in length.

[No more than two meters].

This description seems to say that 0-2 meters is fine, but the actual interval value should be between 1.5-2 meters.

the reason is simple.

well known.

Missiles usually consist of four parts. Or modules:

Warhead,

body structure,

powerplant,

and guidance systems.

Among them, the warhead is a special device for destroying the target, also called a warhead—the place where the combat charge is placed.

The warheads of strategic missiles mostly use nuclear charges, and winged missiles usually use high-energy explosives.

The body structure is the supporting structure that connects the various parts of the missile, that is, the shell and the link of the missile. The literal meaning is easy to understand.

The power plant is the power source for missile flight, and is equipped with propellant and engine.

For example, ballistic missiles generally use solid or liquid rocket motors, and winged missiles usually use turbofans or turbojet engines, etc.

Not to mention the guidance system, Xu Yun designed an ultra-wideband proximity fuze.

These four components add up.

It is a relatively conventional missile.

And these parts are not like the different-dimensional pockets of Doraemon, which can be stuffed into palm-sized pockets no matter how heavy or bulky you are.

in reality.

Except that the projectile structure is regarded as the "shell".

The remaining three modules all need to occupy a certain amount of internal space.

Therefore, even if there is gravitational potential energy to provide kinetic energy, the length of the missile cannot be too short.

Even Xu Yun, a layman who doesn't know much about missiles, subconsciously imagines that the length of the missile will not be less than 1.5 meters.

However, according to Luo Shijun's calculation results.

In order to conform to the relevant equations deduced by the fifth division Qian, the longest missile can only be one meter from the beginning to the end.

This is going to kill me.

Even in 2023, a one-meter missile will require a rather delicate design.

In the current period, if we want to achieve this length, there are only two steps to take:

Either change the material so that the new material meets the parameter requirements within an interval of 1.5 meters.

either

Come up with a whole new missile structure that can be shortened to a meter.

"."

After a while.

Fifth Master Qian asked Luo Shijun:

"Shi Jun, our existing missile program—whether it is the first generation or the fourth generation, under the premise of basic parameters"

"Which solution has the shortest missile body length?"

Luo Shijun's memory is notoriously good in the missile team. At this time, there is no need to retrieve the data and the result is immediately reported:

"Teacher, the shortest missile we have designed is 1.2 meters long, code-named Pandora, and it is the third-generation missile under planning."

"Teacher, this is already the shortest missile we can design, and it is still a preset plan for 20 or 30 years. It is not capable of production now."

"1.2 meters."

Fifth Master Qian frowned slightly when he heard this, and a dignified look appeared on his always amiable round face.

But soon.

This dignified look was replaced by another calm look.

He took a deep breath, calmed down, and said to Luo Shijun:

"Shi Jun, I've already understood the situation. It's really not easy in terms of difficulty, but you don't have to be too nervous."

"After all, the superior department sent our missile team to the base to assist, isn't it precisely because of the various problems that may be encountered during the development of the Jade Sword missile?"

"It is not an accident to develop an accident this time, and it is an accident if there is no accident. This psychological expectation is still necessary."

Hearing Fifth Master Qian's last sentence, which seemed to be a bit of a tongue twister, Luo Shijun's face suddenly showed a hint of consternation.

right.

Didn't they come all the way from the capital to Jinyintan this time to solve the problem of Zhuxian platform?

True.

The issue of missile size really wasn't within their original assumptions.

After all, a lot of high-altitude data can only be collected by meteorological Doppler radar, and the country has never developed a missile platform that stays in the stratosphere for a long time before.

So among the many issues discussed in advance.

Qian Wushi and others have preset many possible problems such as missile propeller, missile elevation angle, missile shaft speed, etc., but the body length has indeed been ignored.

But that's no excuse to panic.

after all

It's not like they haven't encountered a situation more difficult than this.

For example, the No. 1059 missile that was successfully launched last year.

three years ago.

The rabbits officially began to imitate the bear's P2 missile and named it 1059.

Throughout the process, the engine is the key to missile imitation.

But at that time, the rabbits didn't have many design drawings, and the core information was even blank.

But under the leadership of Qian Wushi and others.

The team of the Fifth Academy finally overcame many barriers such as materials, processes, equipment and propellants, and successfully mastered the key technology of the P2 missile liquid rocket engine.

Then imitate near the end.

A test bench is required for the engine to be put into test, but there is no such equipment in China.

Therefore, Xinmin, the chief engine designer at the time, keenly realized that if he did not test the car in China, he would inevitably choke the neck of the independent development of domestic missiles.

In the end he was without any physical assistance.

Relying on only a few written materials, a detailed test bench design task book was abruptly compiled.

After nearly a year of construction work.

The rabbits' first large-scale liquid rocket engine test bench was finally accepted successfully.

This was followed by a year after landing on the test bench.

1059 The missile was launched successfully.

correct.

The 1059 missile had a more famous name later.

called

Dongfeng No. 1.

The entire development process of Dongfeng No. 1 was also full of various accidents, but the rabbits still persisted and resolved it smoothly?

Think here.

The astonishment and panic on Luo Shijun's face immediately subsided a lot.

He took a deep breath and said seriously to Fifth Master Qian:

"Director Qian, I understand, please give me instructions!"

Seeing this, Fifth Master Qian patted him on the shoulder:

"It's good to understand, there is no rush for instructions, go back to your seat first."

Luo Shijun's expression was serious:

"yes!"

After Luo Shijun returned to his seat.

Fifth Master Qian also pushed Xu Yun's wheelchair back to the podium, and copied several structural parameters onto the blackboard:

Missile body length:

0.9-1.0 meters.

quality:

13 kg.

Centroid location:

0.5423.

Side slip angle:

14.9°.

Rudder deviation:

2.0°-4.9°.

Relative mass of the wings:

After a few minutes.

Fifth Master Qian stopped what he was doing and said to everyone:

"Okay, comrades, here is basically the parameter structure calculated by everyone."

A few more seconds passed.

Fifth Master Qian drew a bar below the two parameters of body length and center of mass position, and continued:

"Tackling problems should be easy before difficult, so among these two problems, let's solve the centroid shift first."

"We took the Pandora missile as a sample, and the body length of the missile was reduced to one meter, so it means that its center of mass must be compressed."

"We still list Jx, Jy, and Jz, which are the moments of inertia of the missile relative to each axis of the missile coordinate system."

"ωx, ωy, and ωz are the components of the rotational angular velocity ω of the projectile coordinate system relative to the ground coordinate system on each axis of the projectile coordinate system."

"Then there is."

I saw Fifth Master Qian quickly continued to write down an equation on the blackboard:

Jxdωx/dt+(JzJy)ωzωy=Mx

Jydωy/dt+(JxJz)ωxωz=My

Jzdωz/dt+(JyJx)ωyωx=Mz (Note: Let’s explain again, don’t say that I use formula hydrology, 7 letters are equal to one Chinese character, and this row of letters is replaced by Chinese characters, which is less than half of what I noted.)

It is not difficult to see from the expression.

This is a kinetic equation for a missile rotating around its center of mass.

Then Fifth Master Qian added aerodynamic coefficients cx, cy, and cz to them.

write here.

Fifth Master Qian couldn't help but stop what he was doing.

Facing a middle-aged man with straight eyebrows and a fuller and rounder face than others, he said:

"Huaijin, let me tell you about the next train of thought."

There were more than 20 people at the scene including the liaison officers, and there was only one person with Huai Jin in his name.

This person is the chief designer of the later Hongqi No. 2, Mr. Chen Huaijin——still the youth version pro.

Hearing what Qian Wushi said.

Chen Huaijin immediately stood up from the seat, and accidentally brought the stool down due to excessive movements.

Fortunately, Chai Zhi, who was at the side, had quick eyesight and quick hands, and supported the stool before it fell to the ground.

"."

Chen Huaijin didn't seem to notice her movements, her eyes were fixed on the blackboard tightly.

After a while.

Chen Huaijin organized the language and said:

"Director Qian, I think it is possible to add a moment with a negative sign to the right side of the equation?"

"In this way, the error caused by the center-of-mass pressure on the center of mass can be eliminated."

"This moment can technically be achieved by rolling the missile body, that is, using a tail with a little deflection, so that the missile rotates around the axis at a low speed during flight."

"In a certain period, the specific period value must be calculated. In short, the problem of moving the center of mass forward can be solved by turning one circle within this period."

"At the same time, the total aerodynamic force is also a vector. When it is not the center of mass, it will also produce a moment that makes the missile rotate. When the sum of these two moments is not zero."

Looking at Chen Huaijin who was talking eloquently.

For the first time, Xu Yun experienced Qiao Caihong's feeling in physics class.

This is what it feels like to have a long brain

You also have today.jpg.

no way.

Mentioned earlier.

You asked Xu Yun to calculate some things about fluid mechanics. After all, Xu Yun has taken this course, and mathematical calculations are also common.

But in the field of research and development of missile bodies, he is a real newcomer.

He can understand or understand every word, but he can only express the meaning of the word together with a question mark on his face

certainly.

Although I don't understand the specific principle.

But Xu Yun still has the ability to read words and deeds.

From the frequent nodding of Master Qian at the side, it is not difficult to see that what Chen Huaijin said should be fine, at least it should be generally correct.

In fact, what Xu Yun didn't know was.

The advanced version of the principle mentioned by Chen Huaijin is actually the center of mass principle of the later Hongqi 17 missile steering in the air.

The whole principle can actually be described in one sentence:

The center of mass precedes the center of mass.

The projectile is stable;

The center of mass is after the center of indentation.

The projectile is unstable.

But if the unstable state of the projectile is well controlled, the center of mass can regularly jump back and forth before and after the center of gravity

Then some bugs can get stuck.

This operation is somewhat similar to the Supreme Lord of the Rings in "Lord of the Rings".

When Frodo puts it on, the Ringwraith will find him, and when he unties it, he will lose the target, so you can wear it from time to time to attract monsters.

Then about ten minutes passed.

Chen Huaijin had just finished talking about her thoughts.

Fifth Master Qian nodded in satisfaction and said affirmatively:

"Comrade Huai Jin's idea is very subtle, but on the basis of Comrade Huai Jin, I would like to add a little bit."

"That is, we can actually apply a deflector on the tail of the missile, and generate another moment through deflection and friction."

"This moment is perpendicular to the central axis where the center of mass is located, and at the same time parallel to the airflow ring tangent of the jet port. In addition"

Hearing Fifth Master Qian's words.

Chen Huaijin, who was standing there, was taken aback for a moment.

After a while.

He suddenly slapped himself on the head heavily, oh yo:

"Yes!"

"If a deflector is used to increase a torque, then no matter whether the center of mass moves forward or backward, the heat energy required to be consumed will be much smaller."

"In this way, the margin of the missile can be freed up to place other equipment or propellant!"

Xu Yun still looked OvO:

"Ah yes yes yes."

Afterwards, Master Qian wrote Chen Huaijin's plan directly on the blackboard, and there was another large line of formulas densely packed.

Here we go.

The difficulty of the center of mass can be regarded as the answer.

The center of mass problem has been solved.

The rest is the most intuitive link:

How to reduce the length of the missile?

After all, what the center of mass considers is the displacement of the center of pressure after the missile is reduced to one meter, which belongs to the level of subsequent optimization.

To deal with this optimization, the length of the missile must be solved first.

The reason why Fifth Master Qian solved the problem of the center of mass first was because he considered clearing the mobs first to focus fire on the big boss, and secondly,

Use a relatively simple question to increase everyone's confidence.

Now the mobs have been cleared, and the rest is the master.

Think here.

Fifth Division Qian couldn't help turning his head to look at the deputy team leader Chai Zhi, and asked him:

"Old Chai, what do you think?"

Chai Zhi's age was second only to Fifth Master Qian at the scene, and he was also an extremely experienced old comrade.

After hearing Fifth Master Qian's questioning.

Chai Zhi quickly opened the notebook in front of him and said:

"Director Qian, first of all we need to make one thing clear."

"That is, if the missile wants to reduce its body length to one meter, it is obviously necessary to compress the internal structure of the missile."

"According to my simple estimation, when the warhead warhead is completely smooth, the length of about 10 centimeters can be optimized."

"After all, the U2 reconnaissance plane is different from other planes. Its body shell is very thin-this is one of the few data released by Mao Xiong."

"So I think we can appropriately reduce the capacity of the warhead to reduce the length of some missiles."

Chai Zhi finished speaking.

Some people were silent.

Some frowned.

Some people nodded.

Among those who nodded, Xu Yun was surprisingly included.

mentioned earlier.

The U2 reconnaissance aircraft is a model that is completely used for reconnaissance, so that it can be said to have been castrated in many attributes.

Such as the detection radar mentioned earlier.

Another example is that its landing needs to be guided by a tractor. When it lands, one side of the wing will inevitably wear out when it touches the ground.

Another example.

The body of U2 is extremely thin.

Moreover, in order to dissipate heat from the engine, there is a gap tens of centimeters wide behind the body.

It is not an exaggeration to say.

In the area behind the tail of U2, you can cut a gap with a kitchen knife ten times-this is a true thing that has been tested.

And because of this.

The amount of charge on the warhead of the sniper U2 missile can actually be reduced.

Then through the optimization of the warhead, the length of some missiles can be reduced.

For example, in some military forums of later generations, many people once discussed a question:

How much can the warhead of the Sam-2 missile be reduced to successfully blow up U2?

Although this question is often skewed in the end to whether it hits the fuel tank or the head area, it is similar to whether a 155 howitzer hits a tank from the side or the front.

However, a generally accepted value is

5 kg.

That's right.

The actual warhead charges 135 kg of Sam 2, in fact, only 5 kg of warhead explosives can blow up U2.

That's the case with a Sam 2.

Not to mention that there are four missiles on the Zhuxian Sword Formation.

Under the guidance effect of the ultra-wideband proximity fuze, Xu Yun estimated that the warhead only needs 3 kilograms of explosives.

Counting the shell of the warhead, the mass of the entire warhead should be reduced to 4 kg.

The line of sight returns to reality.

After Chai Zhi finished speaking.

Fifth Master Qian did not show a clear expression on his face, but signaled to Chai Zhi:

"Old Chai, go ahead."

Chai Zhi nodded. Having cooperated with Fifth Master Qian for many years, he knew that Fifth Master Qian had adopted his idea, so he continued:

"In addition to the warhead, there are only the proximity fuze, the engine and the propellant."

"I saw the diagram of the proximity fuze at the Dean Sun Junren's place in the morning, and the total amount is about one finger (the distance between the thumb down and the middle finger up). Basically, there is not much room for optimization."

"As for the power composition of the engine, not to mention, the engine of the micro-missile is so big, we can't reduce it in terms of size or accuracy."

"So theoretically another place that can be optimized is the combustion chamber where the engine stores the propellant."

this time.

There are obviously many more people who agree with it.

Mentioned above.

The rabbits didn't master the rocket engine test stand until last August.

So let's not talk about the theory of the front end of the engine.

The upper limit of equipment accuracy alone has locked the rabbits' engine development to a deadlock.

in this case.

Winged missiles use either rocket motors or air-breathing motors.

Therefore, it is simply impractical to optimize the engine structure-even if someone comes up with a better solution, it is impossible.

After all, the production mold determines the accuracy, unless you can come up with another set of more precise equipment.

Therefore, the only module left in front of Fifth Master Qian and others that can theoretically be optimized is——

The volume of the combustion chamber.

Then Chai Zhi paused, and continued:

"According to our original design, the length of the combustion chamber of the 'Pandora' missile is 39 centimeters, occupying 1/3 of the length of the missile body."

"This length is even longer than the warhead of the missile. If it can be reduced by more than ten centimeters, then the development of a one-meter missile may be realized."

Fifth Master Qian also nodded and looked at the crowd:

"Comrades, does anyone have any different opinions on what Comrade Chai Zhi said?"

Everyone at the scene shook their heads in unison.

"very good."

Seeing this, Fifth Master Qian gave another instruction decisively:

"Since everyone has no problem with this theoretical direction, let's discuss how to reduce the warhead."

"Now is the time for free discussion. Anyone who has an idea can express an opinion. Is there any comrade who can start?"

Fifth Master Qian just finished speaking.

A boy who had not spoken all this time raised his hand.

This person, Xu Yun, met his name when he was introduced by the Fifth Division Qian. The deity is Mr. Shen Zhongfang, the commander-in-chief of China's third-generation medium-to-high-altitude and long-range air defense missile models.

Judging from some resumes published by later generations.

Mr. Shen is a radical in research and development. He often puts forward some ideas that are risky but also profitable. He is quite individual.

For example [an engineer said with a smile, I hope that the 59 modification can be sent to heaven in the future] The source of all evil comes from the mouth of Mr. Shen.

But at that time, he hadn't passed the declassification period, so the report just used "a certain engineer" instead.

Then Fifth Master Qian made a gesture of invitation to him:

"Zhongfang, please tell me."

Seeing this, Shen Zhongfang also stood up from her seat, looking very energetic, and said:

"Director Qian, I have a bold idea."

"Since the warhead is reduced, the dose of propellant must also be reduced, right?"

"So can we replace a more efficient propellant so that it produces the same energy as the original in a smaller volume?"

"Like some kind of special propellant that's being developed."

"Special propellant?"

Fifth Master Qian repeated the word twice, and immediately his expression changed.

As the current general manager of the missile team, he quickly realized what Shen Zhongfang said.

well known.

Tsiolkovsky deduced the ideal velocity formula for a single-stage rocket in 1903:

V=ω×Ln(Mo/Mk).

This is also known as the Tsiolkovsky formula.

Where ω is the jet velocity of the engine.

Ln is a logarithmic expression.

Represents the logarithm to the base e of the natural logarithm.

Ln(Mo/Mk) is expressed as the logarithm of Mo/Mk with e as the base.

What about Mo and Mk.

They are the initial mass of the rocket and the mass when the engine is turned off, that is, when the propellant is exhausted.

So Mo/Mk is called the mass ratio of the rocket. (This formula is very important, it is recommended to insert an eye)

So after the Tsiolkovsky formula came out.

Rocket propellant also began to develop.

Physically speaking.

The propellants used in rocket motors come in two forms:

One is a liquid substance.

The other is a solid substance.

An engine in which both the combustion agent and the oxidizer are in liquid form is called a liquid fuel engine, or a liquid rocket engine.

If both are in a solid state, they are called solid fuel rocket motors or solid rocket motors.

In this period.

Liquid rocket propellants are considered the mainstream of technology, and the status of solid rocket motors is far from that of later generations.

Among them, the first generation of liquid rocket propellants used liquid oxygen plus gasoline, which is a relatively primitive method.

The second generation is liquid oxygen plus alcohol, and this propellant has continued until now:

Its principle is to cool the thrust chamber by means of liquid film cooling and regenerative cooling, and use the high-temperature airflow generated by the decomposition of hydrogen peroxide catalyzed by sodium permanganate to drive the turbo pump for pumping pressurized delivery of propellant .

The thrust of this mode can reach 2.5 tons, which is enough to launch many missiles.

But with the development of science, the propellant is constantly being updated.

For example, a brand-new propellant has appeared in the world at present, called

Mixed hydrazine 50.

Its alias Aerozine50 is a 50/50 mixture of hydrazine and unsymmetrical dimethylhydrazine UDMH, which was developed by General Aviation Jet Company across the sea two or three years ago.

Its propulsion force is indeed much higher than that of the second-generation liquid. In the words of later generations, it is the "son of the version".

The special propellant mentioned by Shen Zhongfang is exactly this raw material.

but

This kind of extremely poisonous substance has a leakage probability of more than 60% in the current domestic pressure vessels, and it is very unstable.

Due to technical barriers, the research on it in China has just started—about last February, the country only mastered the structural formula of this mixture.

From domestic research and development to the present, the success rate of the sample rocket successfully launching is less than 30%.

So it's not a good choice either from the perspective of security or stability.

However, the problem is that besides replacing the propellant, Fifth Division Qian seems to be unable to find any other usable method.

Do you really want to use this?

And just when Fifth Master Qian was hesitating.

From the corner of his eye, he suddenly caught a glimpse of Xu Yun at the side.

at the same time.

The chief's words came to his mind again:

"Just use Han Li as a donkey."

Think here.

Fifth Master Qian couldn't help coughing lightly, turned to look at Xu Yun, and asked him:

"Comrade Han Li, what do you think?"

"Ah I?"

Xu Yun was watching and eating melons in silence, but he was a little surprised when Fifth Master Qian asked him so abruptly.

After recovering.

He subconsciously prepared to shake his head.

After all, he really doesn't know anything about missile design, and it is obviously impossible for you to ask him to say any optimization theory.

But just as the words were about to come out.

In Xu Yun's mind, inexplicably, the waverider technique mentioned by Fifth Master Qian flashed again.

Immediately afterwards.

A news report he had seen in reality came to his mind.

In addition, Qian Wushi said it before.

Xu Yun only needs to be Party A, and he can make any unconstrained request.

"."

So Xu Yun was silent for a moment, and said to Fifth Master Qian:

"Director Qian, I really have an idea, but please don't hit me if you say it."

Note:

In the last few days at the end of the month, ask for a monthly pass. This month is really desperate for changes.

The goal at the beginning of the month should be completed according to the current situation, but it is still three days away from updating, so the flag will not be set. The specific data will be reported on the 31st, and the number of words is also counted outside the episode.