How to turn Chapter 692? (The work is complicated, two chapters are published first, and there is another chapter at 8 p.m.)
“Compared with the Magnus effect, the benefits of a certain rotation are far greater than those of secondary effects such as the Magnus effect. Therefore, the necessary rotation cannot be less, and this rotation is one of the cheapest ways to improve accuracy."
The comrades of Changfeng Factory and Fenglei Factory understood. Come here, why does Gao Zhendong keep talking about stable rotation?
“For example, the problems caused by long projectiles are far beyond the ones we just discussed. For example, there is a problem that can be figured out intuitively without theory. That is long projectiles. The head drop phenomenon during the process of leaving the tube.”
This example is very intuitive. Although they have always made short and thick bullets and have not encountered this problem, it does not affect the two factories at all. Comrades imagined the situation just through Gao Zhendong's narration.
As the missile body becomes longer, the center of gravity moves forward. When the rocket leaves the directional tube, once the center of gravity leaves the mouth of the tube, the missile body has a tendency to fall. And obviously, anyone who has studied junior high school physics can imagine this. Phenomenon, the longer the projectile, the more obvious it is.
For rockets, it means that the direction is crooked as soon as you go out.
"Yes, Chief Engineer Gao's reminder is really the truth, the simplest lever principle, and as the rocket moves more outside the directional tube, the fulcrum becomes farther away from the center of gravity of the missile. This The phenomenon becomes more obvious.”
There is no need to actually test it, just make it up in your head.
Another comrade thought for a while and made a suggestion: "Then we can solve this problem by moving the center of gravity of the rocket as far back as possible so that it leaves the nozzle as late as possible."
Needless to say, Gao Zhendong, some comrades objected first: "It's definitely not possible. Firstly, the structure and function of the rocket determine that it is impossible to move the center of gravity of the rocket to the rear. Secondly, the farther the center of gravity is to the rear, the harder it is for the oncoming enemy." The easier it is for the airflow to affect the flight state of the rocket, the more unstable it will be."
Seeing that this idea did not work, some comrades proposed increasing the initial velocity of the rocket.
Rockets are different from cannonballs. Cannonballs are at their peak when they debut, and the muzzle velocity is when they reach their highest speed. Rockets, on the other hand, move first, then slowly develop and accelerate during flight.
This means that at the beginning, its speed was not large, the projectile had no lift, and the head-drop phenomenon had a greater impact.
This comrade’s idea is to throw the rocket out as fast as possible before he notices it. Let it fly!
Then a comrade did some mental calculations and smiled bitterly: "I can't calculate how fast this speed is for the time being, but the estimated value will already have a significant impact on rockets and even rocket launchers. Moreover, this method does not Solve the problem from the root."
Everyone discussed it for a long time and felt that it was indeed true. After thinking about it, we couldn't find a simple, convenient and cheap way. Finally, we remembered what Gao Zhendong said just now.
"What should I do? I think Chief Engineer Gao just said that the projectile should be rotated while it is still in the launch tube."
It seems that Gao The chief engineer is right, the projectile still needs to be rotated.
The rotating projectile can reduce this effect to a great extent. The precession of the gyro is a good thing. There is a reason why rotation stabilization is used in bullets, artillery shells and rockets.
At this time, the comrades realized a big problem: how to spin this thing in the tube?
When the rocket first starts, the speed is the lowest. Not to mention the tail fin that has not yet unfolded in the tube, even the tip winglets that have stretched out their heads do not have enough power to rotate this thing. .
“Do we still need to use turbine engines? Isn’t this back again?”
This question is actually an old question. I don’t know about others, but the rockets of Lao Maozi’s system and ours , as long as it reaches a certain range, it will start to rotate during the process of exiting the barrel.
Among them, our later foreign trade 80-kilometer 273mm rocket was more interesting. It looked like a box-type launcher, but in fact it did not use a directional tube, but a directional guide rail. Some technologies cannot be used. , the 273 rocket is so heavy that it really can’t be turned using ordinary methods.
In the end, they used a powerful method that worked wonders, and installed a spin motor on the head of the rocket! Use the small rocket motor on the head of the rocket to spin it when it is launched!
Everyone had almost reached the point where they were stuck at this point. Gao Zhendong smiled and said, "It's not difficult actually. If you want to turn it around, wouldn't it be enough to install rifling on the rocket launcher?"
Rifling? Chief Engineer Gao, are you confused with other projects?
Everyone looked at each other in shock, including the comrades of the Land Loading Bureau.
Seeing that no one knew what to say, Gao Zhendong drew a directional tube on the blackboard, and then drew an arc on the directional tube.
"Rifling is just a metaphor. In fact, it is to make a rotating groove on the directional tube of the rocket launcher, and install corresponding bumps on the rocket to be stuck inside. During the outward movement of the rocket, this The bumps force the rocket to rotate. The speed of rotation and the final effect can be determined based on the exit speed of the rocket and the twist of the groove."
How can this be done?
Comrades looked at the abstract "guide groove" on the picture, and their eyes almost fell out.
But I thought and thought, holy shit, it seems like it could really be like this!
First of all, this method can indeed achieve the effect of the rocket spinning during the launch process as needed.
Secondly, this thing has no difficulty or threshold for rockets, and has minimal impact on cost. Finally, it is difficult to process this guide groove, but fortunately, it is processed on the directional tube of the rocket launcher. It is a one-time deal. Once it is processed, the rest of the work is left to the guide block on the rocket launcher. The cost, The processing difficulty is generally acceptable.
The comrades in Changfeng Factory looked at Gao Zhendong and really didn’t know what was in this comrade’s head.
If you want to talk about seemingly high-level theories, research, and analysis, he has them, and they are all in one set. But when it comes to solutions to problems, he is not afraid of all kinds of meat and vegetables. .
This method of adding a groove on the pipe is really not advanced.
But can it solve the problem? able! And it’s very cheap to solve.
No, no, no, this is truly advanced!
"General Engineer Gao, I'm convinced, I'm convinced, this is a good method."
Gao Zhendong smiled and said: "Actually, to solve the problem of rocket accuracy, there is active control. There are ways, such as inertial navigation correction, but that is too expensive and is not realistic now. "
But it doesn't matter if it is unrealistic, just sow the seeds, and they will sprout naturally when the time is right.
Comrades from the Land Loading Bureau laughed and said: "The current range is enough. No matter how far it is, our observation methods cannot support its use."
If 60 kilometers can barely support it, The higher range is actually meaningless. If you can't see it, it means nothing if you can hit it.
Speaking of the long enough range, Gao Zhendong suddenly remembered a hidden danger. He pointed to the second half of the rocket on the blackboard: "You should pay attention to this part. When the rocket engine works long enough, When the projectile is fired, the projectile may be burned through by the high temperature, causing the projectile to drop. Especially Especially because the new propellant has a relatively high combustion temperature, it must be considered in advance when designing. "
Not to mention high combustion temperature propellants, even ordinary propellants, Gao Zhendong knew in his previous life that he was doing 122. This situation also happened when I was working on the company, and it took more than a year to find out the problem and solve it.
It is naturally the best to avoid taking detours.
Comrades from Changfeng Factory and Fenglei Factory wrote down this situation and asked Gao Zhendong: "I remember you said that there are fan-out, ballistic crossing and other situations. How to solve these situations?"
Gao Zhendong shakes He shook his head: "These situations are only possible, but different designs may not necessarily appear, and the solutions are all related to your specific design. When you encounter it, let’s analyze and solve it. If I have to make some suggestions, it is that the rotation, movement, support and other structures must be locked sufficiently during launch while ensuring the rocket’s flight attitude.”< br>
To put it simply, the unevenness of the launch tube on the left and right is still small, but if it is loose, then every shot will really be out of the ordinary.
Comrades from the Land Installation Bureau saw that it was almost done and asked: "General Engineer Gao, do you have any other suggestions or opinions?"
Gao Zhendong thought about it, although he felt it was a little late. However, I still made a suggestion: "If possible, it is recommended to increase the caliber of the large-caliber rocket launcher to more than 250mm."
Comrades from the Land Installation Bureau and the National Defense Work Committee were very surprised as to why Gao Zhendong made this suggestion.
Gao Zhendong explained: "The caliber of the terminally sensitive bomb currently being developed is 110mm. If the large-caliber rocket is only 180mm, it means that its cross-section can only accommodate one terminally sensitive bomb, and a lot of space is wasted. If it is raised to more than 250mm, three of them can be placed side by side in a Z-shaped pattern. "
This is a simple geometric problem. After thinking about it in our minds, we understood that Gao Zhendong was right.
"Can you make the terminally sensitive bomb smaller? 80mm?"
Gao Zhendong shook his head: "No, no matter how small it is, the power cannot be guaranteed, and the sensor is difficult to arrange. The 110mm caliber Almost the limit of existing technology”
The comrades from the Land Installation Bureau thought for a while: "We will take this issue into consideration. If it doesn't work, we will solve it in the next generation."
When it was time to send off the comrades, Gao Zhendong said very solemnly Holding the hands of the comrades from Fenglei Factory: "Comrades, this 130mm rocket launcher with a range of 40 kilometers is very important. I hope you will do a good job."
Then the 180mm one is not important? Comrades from all sides felt a little strange, but to them, regardless of whether Gao Zhendong said this or not, things had to be done. Maybe Chief Engineer Gao just said whatever came to his mind.
(End of this chapter)