Chapter 687 Save money! save money!
With this performance, even if its smoke completely covers my position, I will praise it for its good cover!
The joys and sorrows between people are indeed not the same. I am working hard for basic performance, while others are thinking about trivial matters.
This kind of propellant is not a smokeless propellant, but a typical propellant that adds metal combustible aluminum powder in order to be cheap and have a long range. After combustion, there are not so many particles.
For a certain period of time, it’s not that we don’t want to use smokeless propellants or that we don’t have smokeless propellants, but the smokeless propellants of general double-base propellants are not as powerful as smoked propellants. For that reason, it is not The performance is not very necessary. If you give up the price and it is cheaper than the gain, everyone will choose it.
In fact, early propellants such as rattlesnakes and sparrows were still smoky all the way.
Having said that, in things like rockets, even in the 21st century, there is still no place for smokeless propellants. Air-to-air missiles must be smokeless, mainly to avoid affecting the work of fighter engines as much as possible, not to nice.
So the shortcoming mentioned by Gao Zhendong is not a problem at all in the eyes of Fenglei Chang and other comrades.
"General Engineer Gao, what kind of defect is this? There is no way to burn without smoke." The comrade of Fenglei Factory laughed.
Gao Zhendong said: "Well, what I mean is that it is best not to use this thing for air-to-air missiles. Rocket launchers can be used casually. Strictly speaking, this is not the limit of this propellant, but For rockets, the ultimate burning rate is too high It is not conducive to the performance of the range. I lowered the burning rate, which also affected the specific impulse. In addition, there is another problem with this propellant, that is, the burning temperature is higher than the propellant you are using now. Pay attention to this issue when designing. ”
With the addition of metal burning agent, the combustion temperature will naturally increase. Anyone who has studied chemistry knows that there is a very famous burning agent called thermite.
After listening to Gao Zhendong's words, the comrades of Fenglei Factory did not take the shortcomings explained by Gao Zhendong to heart, but admired Gao Zhendong very much.
We are still groping in the dark, but he has been able to freely adjust it for the necessary performance.
"General Engineer Gao, we will pay attention to this issue and have some experience." There are advantages and disadvantages, and the comrades of Fenglei Factory know it very well. However, this disadvantage is something that can be solved once you know it. Compared to the problem of not being able to rush forward, it is considered a small matter.
After Gao Zhendong said this, he turned to look at the comrades in the Land Loading Bureau.
"If the propellant of 107 is similar to that of 130, you can also consider switching to this propellant. If so, if you want 107 with a 30% range increase, I will consider it a deal."
Gao Zhendong said He also made a joke, but in fact he knew clearly that there would be no difference between the current propellants of 107 and 130.
What’s even funny is that all the rocket launchers planned at this time, not to mention the plans and propellants, all had the same range in the end.
107mm, 8.5 kilometers.
130mm, 10 kilometers.
180mm, hey, it’s still 10 kilometers, so it’s really hard to stretch it.
It can be seen from this incident that any bit of knowledge Gao Zhendong knows is very valuable to the comrades who are currently engaged in rocket launchers.
The comrades of the Land Decoration Bureau did not expect that Gao Zhendong’s problem would not last overnight. He wanted 30%, right? Solve it now!
Everyone has the mentality of looking forward to Shu, and the comrades of the Land Decoration Bureau are no exception: "Does it mean that with your other skills, it can be improved by 50%?"
Gao Zhendong thought about it Thinking, shaking his head: "For 107, I It’s not very recommended to use the technology I mentioned later. This technology will increase some costs. From the original design intention of 107, it is a bit contradictory. What 107 wants is to be extremely simple and cheap, so it is suitable for guerrillas.”
The 107 was designed with this goal in mind. To a certain extent, the tactical mission of the 130 rocket launcher was not original to us, but the 107 rocket launcher was.
To be honest, if I hadn’t fought guerrilla warfare for decades and had a lot of relevant practical experience, I would never have thought of such an even slightly insane artifact as the 107 Fire.
“It doesn’t go up too high above the neck, so it’s easier to look up; it doesn’t go down too low but the hips, so it’s easy to step; not too wide than the shoulders, so it’s easy to pass; the center of gravity is close to the body to prevent twisting of the waist.” With these thirty-two words, the design of 107 The essence is summed up vividly.
So Gao Zhendong thought it was okay to change the propellant, but he felt it was unnecessary to use a more complicated process.
However, for the comrades of the Land Installation Bureau, this matter is obviously "I don't want you to feel, I want me to feel."
"Yeah, we will fully consider your opinion." This is very interesting.
Gao Zhendong didn't care either. It must be best for them to decide this kind of thing.
"Well, whether it's useful or not, let me talk about it first. You can use dual-thrust engines. Of course, you don't need a too complicated dual-thrust configuration on the rocket. As long as it meets the standards and can be used."< br>
The comrades of Fenglei Factory had never heard of this matter: "Double thrust? How to do it? What are the benefits?"
Chief Engineer Gao's ideas really can't keep up, they are all new things.
Okay, let’s start from the beginning. "We can know from Newtonian mechanics that changing the state of motion of an object requires additional work, but maintaining the state of motion of an object is much easier, right? Based on this theory, we can infer that when a rocket is first launched, Sometimes, a big push is needed to make him move. Come on, accelerate to a certain speed, and then maintain this state, you don’t need so much thrust, right?”
Everyone still understands this, or only middle school students understand it. But whether you can make good use of this principle is another matter.
“This is the principle. Rapid combustion starts with high thrust, and slow combustion is maintained with small thrust...”
“This is the principle of multi-stage rockets. How to achieve it in a single-stage engine? ”
"Don't worry about the implementation, it is theoretically feasible. In this way, the working status of the rocket engine can be distinguished, and targeted design can be carried out for different flight stages of the missile."
"It's that simple. I learned this principle in middle school, but I can’t think of it!”
“It’s useless to think about it, you have to do it to be able to do it. Rockets are single-stage, and we don’t think in this direction at all.”
“…”
The comrades in Fenglei Factory had a sudden enlightenment, taking notes and engaging in heated discussions.
Comrades from the National Defense Work Committee and the Land Loading Bureau looked at this scene and couldn't help but twitching on their faces. Did Chief Engineer Gao open the door to a new world for them?
And it sounds like the door is separated by a layer of window paper, which is not strong at all.
But everyone just didn’t expect it!
Many times, once the theoretical things are broken down, you will find that it is actually very simple, but the difficulty is breaking through the window paper of the theory.
"Chief Engineer Gao, how to achieve this dual thrust? Two-stage rocket?"
In fact, if we do not consider the number of stages of the rocket, but consider the rocket as a whole, then the multi-stage rocket is actually a typical engineering implementation of multi-stage thrust.
But this thing obviously cannot use multi-stage rockets, otherwise the comrades who make rockets will not even know the principles of multi-stage rockets. The biggest reason is that they have not thought about using single-stage rocket engines. Make a dojo in a screw shell.
Single-stage rockets are clear, and multi-stage thrust is also clear.
Single-stage rocket + multi-stage thrust? What is this? Never thought about it.
Gao Zhendong smiled and shook his head: "Definitely not. The multi-stage rocket used on this thing is the price of tofu on a plate, haha. A single-stage rocket, a two-stage pill. This two-stage pill The columns can be made of the same propellant, or two different propellants. In order to save the most money, you can use the new propellant I gave you for startup and the old propellant for maintenance. In fact, the effect is not bad. "< br>
When the comrades of Fenglei Factory heard this, they couldn't help but sigh that Chief Engineer Gao's ideas were so clear and ever-changing, not to mention that this idea was useful and possible to be realized.
The comrades of the Land Decoration Bureau are heartbroken, this is a misguided approach! Don't do it!
General Engineer Gao is good at everything. The only drawback is that wherever he can make do, he tries to make do and save money.
“Comrades, regardless of saving money, how are we going to realize this dual thrust?” The comrades from the Land Installation Bureau changed the subject, temporarily stopping the comrades from Fenglei Factory from going too far on the “wrong” road. The act of going further and further.
Gao Zhendong smiled and said: "No matter what kind of propellant is used, the propellant in the take-off stage must increase the burning area, but it must also ensure stable combustion and be as easy to process as possible. So my suggestion is, The propellant in the take-off stage uses a star-shaped combustion surface and is designed for internal combustion. The sustaining stage uses your current round combustion surface, which is also internal combustion.”
The internal combustion here is different from the internal combustion of a car engine. It refers to combustion starting from the center of the grain column and outward. The circle and star shape here refer to the shape of the internal hollow on the cross section of the grain column, which determines the engine The initial burning area during ignition.
The larger the combustion area, the greater the natural thrust. The propellant of rifle bullets is made into pieces one by one or piece by piece. This is the reason.
Among them, circular internal combustion is the simplest and cheapest, but its starting performance is not good, and the initial combustion area is the smallest.
The star-shaped burning surface is different. It can maximize the burning area from the beginning. It is possible to burn with equal area or even with reduced area.
Under Gao Zhendong's explanation with pictures and texts, the comrades of Fenglei Factory have mastered this technology, and they have also expanded it based on their own professional knowledge.
"General Engineer Gao, since the starting thrust is so important, why not make the starting section internal and external combustion? That way the starting thrust will be greater."
Well, this comrade understands it.
“The main star-shaped combustion surface is enough. Not only is it meaningless to increase the size, it will bring new problems. In the case of internal combustion, the shell will only be burned to the end of the combustion. For the shell The high-temperature performance requirements are much lower, and the internal and external combustion directly burns the engine casing from the beginning, which poses a great challenge to the high-temperature performance of the casing and will bring about many other problems.”
( End of chapter)