Looking at Luo Shijun with a somewhat solemn expression.
Qian Wushi's expression didn't change much, but there was a vague premonition in his heart.
Luo Shijun was his direct disciple when he was at Caltech. He received a doctorate from Caltech as early as 1950.
Even looking at the pneumatic field across the country.
Luo Shijun is also considered a top pneumatic expert, and is even regarded as his successor by Master Qian.
If not.
Qian Wushi will not let Luo Shijun serve as the leader of the theory team.
To know.
There are still one or two seniors in the entire theoretical group who are more senior than Luo Shijun, such as deputy group leader Chai Zhi.
For Luo Shijun to serve as the team leader is a testament to his ability.
And now being able to ask Luo Shijun to name the problematic power link is equivalent to a person encountering a problem in the field in which he is most proficient...
Think of this.
Fifth Division Qian immediately took the report from Luo Shijun's hand and read it carefully.
"...."
About five or six minutes passed.
Qian Wushi just put down his report again thoughtfully.
He first slowly looked around the scene, and finally returned his gaze to Luo Shijun, and asked his disciple:
"Shi Jun, that is to say, if you want to have a missile with the parameters of the spinning body that we need, the whole body length must be between 90 and 100 centimeters?"
Luo Shijun nodded solemnly:
"Yes, teacher."
See this situation.
Xu Yun on the side did not need Master Qian's explanation and immediately understood what Luo Shijun was talking about in the power link.
I see......
Mentioned earlier.
Due to restrictions on the airship's carrying capacity and retention height, the missiles carried by the 'Zhuxian Sword Array' cannot exceed two meters in length.
[Not 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.
As we all know.
Missiles usually consist of four parts....or modules:
warhead,
projectile structure,
powerplant,
and guidance system.
The warhead is a special device for damaging targets, also called a warhead - it is the place where combat charges are placed.
The warheads of strategic missiles mostly use nuclear charges, while winged missiles usually use high-energy explosives.
The missile body structure is the support structure that connects the various parts of the missile, that is, the shell and links of the missile. The literal meaning is easy to understand.
The power unit 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 turbofan 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 Doraemon's extra-dimensional pockets, which can be stuffed into a palm-sized pocket no matter how heavy or large you are.
in reality.
In addition to the missile body structure being 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 much shorter.
Even a layman like Xu Yun, who doesn't know much about missiles, subconsciously imagined that the length of the missile would not be less than 1.5 meters.
However, according to Luo Shijun's calculation results.
To comply with the relevant equations deduced by Master Qian, the missile can only be one meter long from beginning to end...
This will cost my life.
Even in 2023, a one-meter missile will require quite sophisticated design.
In order to achieve this length in this period, there are only two steps to take:
Either change the material so that the new material meets the parameter requirements within the range of 1.5 meters.
Either...
Come up with a completely new missile structure that can be shortened to one meter.
"...."
After a while.
Master Qian asked Luo Shijun:
"Shi Jun, our current missile program - whether it is the first generation or the fourth generation, as long as there are basic parameters..."
"Which solution has the shortest missile body length?"
Luo Shijun's memory is notoriously good in the missile team. At this time, he immediately reported the results without retrieving data:
"Teacher, the shortest missile we have designed is 1.2 meters long, code-named Pandora, and is the planned third-generation missile."
"Teacher, this is already the shortest missile we can design, and it is a preset plan for twenty or thirty years later. We simply don't have the ability to produce it now..."
"1.2 meters....."
Qian Wushi frowned slightly when he heard this, and a trace of solemnity appeared on his always amiable round face.
But soon.
This solemn look was replaced by another calm look.
He took a deep breath, calmed down, and said to Luo Shijun:
"Shi Jun, I already understand the situation. The difficulty is indeed not easy, but you don't need to be too nervous."
"After all, the superior department sent our missile team to the base to assist, isn't it just because we may encounter various problems during the development process of the Zhuxianjian missile?"
"It's not an accident if there is an accident this time. It's an accident if there is no accident. You still have to have this psychological expectation."
After hearing Qian Wushi's last words, which seemed to be a bit of a tongue twister, Luo Shijun's face suddenly showed a trace of obvious astonishment.
right.
Didn't they come all the way from the capital to Jinyintan to solve the problem of the Zhuxian Platform?
True.
The problem of missile size is indeed not within their original preset range.
After all, a lot of high-altitude data can only be collected by meteorological Doppler radar, and China has never developed a missile platform that stays in the stratosphere for a long time.
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. The body length has indeed been ignored.
This chapter is not finished yet, please click on the next page to continue reading the exciting content! But this is no excuse to panic.
after all.....
It's not like they have never encountered situations more difficult than this.
For example, the No. 1059 missile was successfully launched last year.
three years ago.
The Rabbits officially began to imitate the Mao Xiong 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 completely blank.
But under the leadership of Qian Wushi and others.
The team from 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 the imitation comes to an end.
A test bed is required to put the engine into testing, but there is no such equipment in China.
Therefore, Xinmin, the chief designer of the engine at the time, was keenly aware that not testing the engine domestically would inevitably strangle the independent development of domestic missiles.
In the end, he did it without any physical assistance.
Relying only on a small amount of textual information, a detailed commissioning document for the design of the test bench was written out of the blue.
After nearly a year of project construction.
Rabbits’ first large-scale liquid rocket engine test bed was finally successfully accepted.
Then one year after the test bed was put into operation.
1059 missile launched successfully.
correct.
The 1059 missile later had a more famous name.
It's called...
Dongfeng No.1.
The entire development process of Dongfeng-1 was also full of various surprises, but didn't the rabbits persist and successfully solve it?
Think of this.
The shock and panic on Luo Shijun's face immediately subsided a lot.
He took a deep breath and said seriously to Master Qian:
"Director Qian, I understand, please give me instructions!"
Master Qian saw this and patted him on the shoulder:
"As long as you understand, don't rush the instructions. Just go back to your seat first."
Luo Shijun's expression became solemn:
"yes!"
After Luo Shijun returned to his seat.
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:
13kg.
Center of mass position:
0.5423.
Side slip angle:
14.9°.
Rudder deflection:
2.0°-4.9°.
Relative mass of wing:
...
A few minutes later.
Master Qian stopped what he was doing and said to everyone:
"Okay, comrades, here is basically the parameter structure that everyone has calculated."
A few more seconds passed.
Qian Wushi drew a horizontal bar under the two parameters of body length and center of mass position, and continued:
"Problems should be dealt with easier first and then harder, so of these two problems, let's first solve the problem of center of mass shift."
"We take the Pandora missile as a sample. If the missile body length is reduced to one meter, then its center of mass position must be compressed."
"We still list Jx, Jy, Jz, which are the moment of inertia of the missile relative to each axis of the missile body coordinate system..."
"Wx, wy, and wz are the components of the rotational angular velocity w of the missile coordinate system relative to the ground coordinate system on each axis of the missile coordinate system."
"Then there is..."
Qian Wushi quickly continued to write an equation on the blackboard:
Jxdwx/dt (Jz?Jy)wzwy=Mx
Jydwy/dt (Jx?Jz)wxwz=My
Jzdwz/dt (Jy?Jx)wywx=Mz (Note: Let me explain again, don’t say I am using formula hydrology, 7 letters are equal to one Chinese character, and this row of letters is not more than half of what I noted when converted to Chinese characters.)
It is not difficult to see from the expression.
This is a dynamic equation of a missile rotating around its center of mass.
Then Qian Wushi added aerodynamic coefficients cx, cy, cz to them.
Write here.
Master Qian couldn't help but stop what he was doing.
He said to a middle-aged man in the audience who had firm eyebrows and a face that was fuller and rounder than others:
"Huaijin, please tell me the next idea."
There were only about twenty people on site including liaison officers, and there was only one person with Huai Jin in his name.
This person is the later chief designer of Hongqi No. 2, Mr. Chen Huaijin - still the youth version of pro.
Hearing these words from Master Qian.
Chen Huaijin immediately stood up from his seat, and his movements were too big and he accidentally knocked over the stool.
Fortunately, Chai Zhi at the side had quick eyes and quick hands and caught the stool before it fell to the ground.
"...."
Chen Huaijin seemed not to notice his actions, his eyes fixed on the blackboard.
After a while.
Chen Huaijin organized his words and said:
"Director Qian, I think it is possible to add a torque with a negative sign on the right side of the equation?"
"In this way, the mathematical error caused by the center of mass to the center of mass can be eliminated."
"This torque can technically be achieved by rolling the missile body, that is, using a tail with a little deflection to make the missile rotate around its axis at a low speed during flight."
"In a certain period...the specific period value must be calculated. In short, if it rotates once within this period, the problem of the center of mass moving forward can be solved."
"At the same time, the total aerodynamic force is also a vector. When it does not pass through the center of mass, it will also generate a torque to rotate the missile. When the sum of these two torques is not zero..."
Looking at Chen Huaijin talking eloquently.
For the first time, Xu Yun experienced the feeling of Qiao Caihong when he was listening to physics class.
So this is what it feels like to have a brain...
You also have today.jpg.
no way.
Mentioned it earlier.
It's okay if you ask Xu Yun to calculate some fluid mechanics. After all, Xu Yun has taken this course as an elective, and the mathematical calculations are also common.
But when it comes to the field of missile body development, he is a real newcomer.
He can understand or understand every word, but when they are connected together, he can only express a question mark...
certainly.
Although I don’t understand the specific principle.
This chapter is not over yet, please click on the next page to continue reading! But Xu Yun still has the ability to observe words and emotions.
It is not difficult to see from the frequent nodding of Master Qian on the side that there should be nothing wrong with Chen Huaijin's idea, at least it should be generally correct.
In fact, what Xu Yun didn't know was.
The advanced version of this principle mentioned by Chen Huaijin is actually the center-of-mass principle of the later Hongqi-17 missile's aerial steering.
The whole principle can actually be described in one sentence:
The center of mass is before the center of compression.
The projectile is stable;
The center of mass is behind the center of compression.
The projectile is unstable.
But if the unstable state of the projectile is controlled well, the center of mass can jump regularly before and after the center of mass...
Then some bugs can get stuck...
This operation is somewhat similar to the One Ring in "Lord of the Rings".
When Frodo puts it on, the Ringwraiths will find him, and when he takes it off, he will lose his target, so he can wear it and take it out to attract monsters...
About ten minutes passed.
Chen Huaijin just finished speaking all his thoughts.
Qian Wushi nodded with satisfaction and affirmed:
"Comrade Huaijin's idea is very subtle, but on the basis of Comrade Huaijin, I would like to add a little bit."
"That is, we can actually apply a deflector on the tail of the missile to generate another torque through deflection and friction..."
"This moment is perpendicular to the central axis where the center of mass is located, and parallel to the tangent line of the airflow ring at the jet port. In addition..."
Hearing what Qian Wushi said.
Chen Huaijin, who was standing in his position, was stunned for a moment.
After a while.
He suddenly slapped his head hard and made an ooh sound:
"Yes!"
"If you use a deflector to increase a moment, whether the center of mass moves forward or backward, the heat energy that needs to be consumed will be much smaller."
"In this way, the remaining space of the missile can be used to install other equipment or propellant!"
Xu Yun still looked OvO:
"Ah, yes, yes..."
Then Qian Wushi directly wrote Chen Huaijin's plan on the blackboard, which was densely packed with a large line of formulas.
At this point.
The difficult problem of center of mass finally has an answer.
The center of mass problem is solved.
The rest is the most intuitive link:
How to reduce the length of missiles?
After all, the center of mass considers the displacement of the center of mass after the missile is reduced to one meter, which is a level of subsequent optimization.
To handle this optimization, you must first solve the length of the missile.
The reason why Qian Wushi solved the center of mass problem first was because he wanted to clear out the mobs first so that he could focus on the big boss, and secondly...
Use a relatively simple question to boost everyone's confidence.
Now that the mobs have been cleared, the only one left is the real owner.
Think of this.
Qian Wushi couldn't help but turned to look at the deputy team leader Chai Zhi and asked him:
"Lao Chai, what do you think?"
Chai Zhi's age is second only to Qian Wushi at the scene, and he is also an extremely experienced veteran comrade.
After hearing Qian Wushi's question.
Chai Zhi quickly opened the notebook in front of him and said:
"Director Qian, first we need to be clear about something."
"That is, if the missile wants to reduce its body length to one meter, it is obvious that the internal structure of the missile must be compressed."
"According to my simple estimation, if the warhead warhead is completely smooth, the length of the warhead can be optimized by about 10 centimeters."
"After all, the U2 reconnaissance aircraft is different from other aircraft. Its body shell is very thin and light - 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 part of the length of the missile."
Chai Zhi finished speaking.
Some people at the scene were silent.
Some people frowned.
Some people nodded.
And among the people who nodded, Xu Yun was surprisingly included.
Mentioned earlier.
The U2 reconnaissance aircraft is a model that is entirely used for reconnaissance, so that it can be said to have been castrated in many attributes.
For example, the detection radar mentioned before.
Another example is that its landing needs to be guided by a tractor. When it lands, one wing will inevitably come into contact with the ground and cause wear.
Another example...
The body of the U2 is extremely thin.
And in order to dissipate heat from the engine, there is a gap tens of centimeters wide behind the body.
Not an exaggeration.
In the area behind the tail of U2, you can cut a gap ten times with a kitchen knife - this is a true thing that has been tested.
That's why.
The amount of powder on the warhead of the sniper U2 missile can actually be reduced.
Then through the optimization of the warhead, part of the missile length can be reduced.
For example, many people discussed an issue on some military forums in later generations:
How much powder can the warhead of the SA-2 missile be reduced to, and can it still successfully blow up the U2?
Although this problem often ends up being whether it hits the fuel tank or the head area, similar to whether the 155 howitzer hits the side or the front of a tank.
But a more recognized value is...
5kg.
That's right.
The actual warhead charge of Sam 2 is 135 kilograms. In fact, as long as it has 5 kilograms of warhead explosives, it can blow up the U2.
This is true for a Sam 2.
Not to mention 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 needed 3 kilograms of explosives.
Including the shell of the warhead, the mass of the entire warhead should be reduced to 4 kilograms.
His eyes returned to reality.
After Chai Zhi said these words.
Master Qian's face did not show a clear expression, but he signaled to Chai Zhi:
"Lao Chai, please go on."
Chai Zhi nodded. Having worked with Qian Wushi for many years, he knew that Qian Wushi had adopted his idea, so he continued:
"In addition to the warhead, only the proximity fuze, engine and propellant parts are left."
"I saw a diagram of the proximity fuze from Dean Sun Junren and his colleagues in the morning. It is only about the distance between a finger press (thumb down, middle finger straight up). Basically, there is not much room for optimization."
"As for the power composition of the engine, let alone the power composition of the engine. The engine of the micro missile is only so big, and we cannot reduce it in terms of size or accuracy."
"So in theory, another place that can be optimized is the combustion chamber where the propellant is stored in the engine."
This time.
There were obviously many more people on the scene who agreed.
It was mentioned above.
It was not until August last year that the Rabbits mastered the rocket engine test bench.
So let’s not talk about the theory of the engine front end at the moment.
Just the upper limit of equipment accuracy has locked up the rabbits' engine development.
in this case.
Winged missiles use rocket engines or air-breathing engines.
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, in front of Qian Wushi and others, the only modules that can theoretically be optimized are——
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, which occupies 1/3 of the missile's body length."
"This length even exceeds the warhead of the missile. If it can be reduced by more than ten centimeters, then the development of a one-meter missile will be possible."
Master Qian also nodded and looked at everyone:
"Comrades, does anyone have any different opinions on what Comrade Chai Zhi said?"
Everyone at the scene shook their heads.
"very good."
Upon seeing this, Master Qian decisively gave another instruction:
"Since everyone is okay with this theoretical direction, let's discuss how to reduce the warhead."
"This is free discussion time. Anyone who has an idea can express his opinion. Is there any comrade who can start?"
Qian Wushi just finished speaking.
A boy who had remained silent raised his hand.
This person Xu Yun knew his name when he was introduced by Qian Wushi. He is Mr. Shen Zhongfang, the commander-in-chief of China's third-generation mid-to-high-altitude long-range air defense missile model.
Judging from some resumes published later.
Mr. Shen is a radical in terms of research and development. He often puts forward some risky but profitable ideas and is quite individual.
For example, [an engineer laughed and said that he hopes to send the 59 to heaven in the future]. This source of all evil comes from the mouth of Mr. Shen.
However, he had not passed the declassification period at that time, so the report just used "a certain engineer" instead.
Then Qian Wushi made an invitation gesture towards him:
"Zhongfang, please speak."
Seeing this, Shen Zhongfang also stood up from his seat. He looked very energetic and said:
"Director Qian, I have a bold idea."
"Since the warhead is reduced, the propellant dose must also be reduced, right?"
"So can we replace it with a more efficient propellant that can produce the same energy in a smaller volume?"
"Such as some... special propellant being developed."
"Special propellant?"
Qian Wushi repeated the word twice, and his expression suddenly changed.
As the current head of the missile team, he quickly realized what Shen Zhongfang said.
As we all know.
Tsiolkovsky derived the ideal speed formula for a single-stage rocket in 1903:
V=wxLn(Mo/Mk).
This is also known as Tsiolkovsky's formula.
where w is the jet speed of the engine.
Ln is a logarithmic expression.
Represents the logarithm with the natural logarithm e as the base.
Ln(Mo/Mk) is expressed as the logarithm of Mo/Mk with e as the base.
Where are 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 used up.
So Mo/Mk is called the mass ratio of the rocket. (This formula is very important, it is recommended to check it)
So after the Tsiolkovsky formula came out.
Rocket propellants also began to develop.
In terms of physical form.
Rocket engines use propellant in two forms:
One is a liquid substance.
The other is solid matter.
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.
At this time.
Liquid rocket propellant is considered the mainstream in technology, and the status of solid rocket motors is far from as high as that of later generations.
Among them, the first generation of liquid rocket propellant used liquid oxygen plus gasoline, which was considered a relatively primitive method.
The second generation used liquid oxygen plus alcohol, and this propellant continues to this day:
Its principle is to use liquid film cooling and regenerative cooling methods to cool the thrust chamber, and use the high-temperature airflow generated by the catalytic decomposition of hydrogen peroxide by sodium permanganate to drive the turbine pump for pump-pressure pressurized delivery of propellant.
.
The thrust of this mode can reach 2.5 tons, which is enough to launch many missiles.
However, with the development of science, propellants are constantly being updated.
For example, there is currently a brand-new booster in the world called...
Hydrazine 50.
Its other name is Aerozine 50, which is a 50/50 weight part mixture of hydrazine and ununiform dimethylhydrazine UDMH. It was developed by the General Aviation Jet Company across the sea two or three years ago.
Its boosting power is indeed much higher than that of the second-generation liquid. In the words of later generations, it is the "son of the version". It is not necessary for those who are awesome.
The special propellant Shen Zhongfang mentioned is exactly this kind of raw material.
but......
This extremely toxic substance has a leakage probability of over 60% in domestic pressure vessels and is very unstable.
Due to technical barriers, domestic research on it has just started - it was only in February last year that the country mastered the structural formula of this mixture.
This chapter is not over yet, please click on the next page to continue reading! From domestic attempts at research and development to now, the success rate of sample rockets successfully launching into space is less than 30%.
Therefore, this is not a good choice regardless of security or stability.
However, the problem is that apart from replacing the propellant, Qian Wushi seems to have no other way to use it.
Do you really need to use this?
And just when Master Qian was hesitating.
From the corner of his eye, he suddenly caught a glimpse of Xu Yun beside him.
at the same time.
The chief's words came to mind again:
"You can just use Han Li like a donkey..."
Think of this.
Master Qian could not help but cough slightly, turned to look at Xu Yun, and asked him:
"Comrade Han Li, what do you think?"
"Ah I?"
Xu Yun was silently watching the meal, but he was suddenly surprised when Qian Wushi asked him so abruptly.
After regaining consciousness.
Subconsciously, he was ready to shake his head.
After all, he really knows nothing about missile design, and it is obviously impossible for him to tell you any optimization theory.
But just as the words were about to come out.
In Xu Yun's mind, the wave-riding body technology that Master Qian mentioned before flashed inexplicably.
Immediately afterwards.
A news report he had seen in real life appeared in his mind.
In addition, Master Qian Wu said before.
Xu Yun only needs to be Party A, and he can make any arbitrary requests.
"..."
So Xu Yun was silent for a moment and said to Master Qian:
"Director Qian, I do have an idea, but don't hit me if you tell me..."
........
Note:
In the last few days at the end of the month, please give me some monthly tickets. This month is really full of updates.
The goal at the beginning of the month should be completed according to the current situation, but there are still three days left to update, so I won’t set a flag. The specific data will be reported on the 31st, and the extra chapter is also counted as a word count.