Chapter 400 Self-Forged Fragments
"Because this will destroy the velocity gradient that has been matched to the liner, causing the metal jet to accumulate and break. In this way, the penetration of the ammunition will decrease. The most troublesome thing is that this decrease is random and the range of variation is very large."

Gao Zhendong explained the reason, and Professor Luo and others finally understood that there was such a problem.

Another student asked a question that is often misunderstood: "Chief Engineer Gao, is this molten metal flow also so sensitive to fracture? Isn't there a saying that if you cut the water with a knife, the water will flow more? Metal flow can also be considered as water flow, right?"

Before Gao Zhendong could answer, Professor Luo started to scold him: "Go back and read your book! Metal jet is not molten metal. The metal that makes up the metal jet is still solid. The metal itself is not melted."

Although he felt that the student's mistake was outrageous, Gao Zhendong did not say much on the matter. He felt that it would be inappropriate to say anything and that Professor Luo should handle it himself.

However, this mistake, which this student as a professional should not have made, is indeed easy for many non-professionals to get confused about. The problem lies in the description of armor-piercing in general books and periodicals - "high-temperature metal jet". If you are not a professional, anyone will be confused.

Even some mediocre books and magazines actually describe the armor-piercing mechanism of shaped-charge projectiles as "the fuse melts to form a high-temperature metal jet", which makes ordinary people even more confused.

After Professor Luo finished scolding his student, he turned around and continued to discuss the grenade problem with Gao Zhendong: "Chief Engineer Gao, can we re-match the velocity gradient for the reflected blast wave and make use of this part of the velocity?"

Gao Zhendong shook his head. "It's difficult. Due to the prefabricated fragments or projectiles, the reflected waves are random, and it's difficult to achieve an ideal match."

Not to mention this time, the hypothesis proposed by Professor Luo had not been resolved until Gao Zhendong traveled through time.

To some extent, unpredictable penetration depth is more troublesome than shallow penetration depth. The latter can work wonders with great effort, but the former cannot be put into practical use.

Professor Luo was quite regretful: "Then it seems that we have no choice but to give up anti-light armor?"

Gao Zhendong shook his head again: "No, there is still a way."

He shook his head this time, which made Professor Luo overjoyed: "Mr. Gao, if you have any ideas, please guide us."

Gao Zhendong did not give a direct answer, but first analyzed for Professor Luo how to balance anti-personnel while ensuring a certain armor-piercing capability: "In principle, as long as the fragments are not placed in the micro-element acceleration charging section of the charge liner, the influence of the reflected waves caused by the fragments on the armor-piercing depth can be greatly avoided or weakened."

In fact, there is another way, but that method will increase the complexity of the grenade and take up space for the charge, which is undoubtedly adding insult to injury for the 35mm grenade, which has a limited charge.

So Gao Zhendong did not mention that method, but chose a simpler and more direct one.

Professor Luo didn't quite understand: "Director Gao, which section is this micro-acceleration charge section you are talking about?"

Gao Zhendong has now become somewhat accustomed to this cognitive gap between the two. He did not show an expression that would embarrass Professor Luo, but instead gave a relatively simple and direct solution.

"Simply put, the fragments are placed from the bottom of the warhead to a height no higher than the top of the liner."

Gao Zhendong was drawing as he spoke, and Professor Luo understood it at a glance. It turned out to be so simple?
In fact, the principle is complicated to explain, but the solution is really that simple.

However, he also expressed some concerns about this structure: "Mr. Gao, this structure requires a larger aspect ratio for the grenade. Our grenade cannot be made long to begin with. In this case, isn't the change too big?"

If the explosive section wants to have enough fragments, it needs a certain length to arrange the fragment area. In this way, combined with the length of the charge liner and nose cone, the bullet appears too long and thin. All the determined designs have to be changed, and the effect may not be good.

Gao Zhendong smiled and said, "We don't use the traditional shaped-charge armor-piercing warhead. This grenade is only 35mm, and the effect won't be very good if it's made that way. Let's change the warhead."

"Change one?" Professor Luo was still a little surprised. New things, another new thing!
"We're working on an explosively formed projectile, or a self-forged fragmentation warhead."

Gao Zhendong wrote down the two names on the paper.

If the words "self-forged fragments" seem a bit mysterious and difficult to understand, then the "explosively formed projectile" is much easier to understand.

"Mr. Gao, what is the specific principle of this explosively formed projectile?" Professor Luo asked. He really didn't understand it.

The principle of self-forging fragmentation bombs was actually proposed in 1936, but large-scale research on it did not begin until the 60s, and it did not really mature until the 70s, so Professor Luo and his colleagues knew nothing about it.

"In principle, it's the same as the shaped charge liner. Both use a conical or similar shaped charge liner to concentrate the energy from the explosive explosion to attack the armor. But I've studied it and found that the taper of this charge liner is much smaller than that of the shaped charge liner. If the shaped charge liner is a funnel, then you can think of this charge liner as a shallow plate." Looking at the structural diagram drawn by Gao Zhendong on paper, Gao Zhendong was thoughtful enough to mark the structure and size of the charge liner. Professor Luo frowned in thought.

After thinking for a while, he slapped his thigh and said, "Yes, yes, yes, this is a good idea! With this angle of charge liner, it is possible to form a high-speed penetrator in the shape of a projectile! Use this penetrator to penetrate armor! Moreover, with this angle of charge liner, the requirement for the aspect ratio of the projectile is also greatly reduced."

Gao Zhendong said: "For this grenade, anti-personnel is the main function, and anti-armor can be 50mm to 80mm. This penetration depth can ensure the destruction of enemy light armored vehicles. As for greater penetration depth, there are other weapons to achieve this."

In fact, in Gao Zhendong's previous life, the rifle-mounted grenades that we finally put into practical use had a variety of ammunition. Regardless of the production conditions, costs and other factors at that time, this all-round bullet that covers anti-armor and lethality is sufficient for the time being.

Although Professor Luo was tempted by the "other weapons" mentioned by Gao Zhendong, he wisely did not ask. Since Mr. Gao said there were some, then they must be there, and there was no need to ask any other questions.

The more Professor Luo pondered Gao Zhendong's plan, the more he found it ingenious: "This structure is so clever. Although the armor-piercing ability may be reduced, it is deeper than our current design. Moreover, according to your theory, the consistency of its penetration depth is also much more stable."

Gao Zhendong smiled and said, "The strength of this bullet is not in the size of its armor-piercing power, but in the fact that it can maintain its armor-piercing ability even when the blast height changes greatly. At the same time, the weight, integrity and consistency of its self-forged projectile can ensure a very good aftereffect."

This is also the biggest advantage of self-forged fragments. They are insensitive to blast height. Unlike the shaped charge warhead, which requires an optimal blast height, this thing does not need it. Its blast height can even be as high as 1000 times the caliber. Under various blast heights, a high-speed heavy projectile with a basically consistent shape and initial velocity is formed by the overall shape of the charge cap. Once the projectile is formed, its armor-piercing mechanism is somewhat similar to that of an armor-piercing projectile.

After this heavy projectile penetrates the armor, the aftereffect is very good, which is its second advantage.

In fact, it is a bit of a waste to use this thing on rifle grenades. Its special advantages determine that its greatest use lies elsewhere.

Professor Luo couldn't think of these things now: "Mr. Gao, what is the use of this big explosion?"

Needless to say, he understood the benefits of a good aftereffect, but he could not quite remember the usefulness of a high explosion.

Anyway, they are all impact fuses, so how high can the maximum explosion height be? However, the advantage of not being picky about the explosion height is really good.

Gao Zhendong said: "For the current grenade, this benefit is not very significant, but."

"But what?" Professor Luo is quite dissatisfied with people like you who are half-hearted.

"How about this, let's ignore it for now. You first fix the grenade hanging on the gun. When it's done, we'll see if we can ask the Defense Work Committee for a project. We'll work on something else. Then you'll know the benefits of a large blast height. It just so happens that I'm going to teach at your school. This project is my gift to Beijing University of Technology, hahaha."

Gao Zhendong caught a few fish by chance. It is too early to say it now. It will affect the mentality of Professor Luo and others. It is not a good thing for the development of gun-mounted grenades.

Professor Luo was very happy to hear this. Wow, Chief Engineer Gao really has a lot of good things here. Before he finishes one thing, the second one comes.

The only drawback is that Mr. Gao only told me half the story, which made me feel itchy.

He had to finish the task at hand quickly, because the next project was already beckoning to him. He did not doubt that Gao Zhendong could not get the project, or that the project he got was meaningless, and that Chief Engineer Gao had the leisure to waste his time with him.

He immediately patted his chest and made a promise: "Don't worry, Mr. Gao. With your guidance today, I am confident that I can basically complete the gun-mounted grenade within a month. I am very interested in this new topic you mentioned."

Even if Gao Zhendong did not mark the dimensions and data on the drawing, Professor Luo, who had already received guidance on the core principles, was confident that he could complete the research on the grenade within a month. The copper charge cap is easy to process and the experiment can be done very quickly.

Gao Zhendong smiled and said, "Then I will wait for Professor Luo's good news."

If he could really make what he envisioned, then combined with the second-generation tanks, individual anti-tank missiles, disposable rocket launchers, etc. that he was participating in and promoting, the fear of the steel torrent in the north could basically be reduced to a minimum!
I will make sure you never come back!
By then, even if the two sides completely fall out, we will be much more confident and we will be able to free up our hands to do more other things.

　Chapter 2 is in the afternoon today.

　　I'll pick out a few interesting photos from the road and post a separate chapter or an Easter egg chapter for everyone to see.

　　I still need to study how to post Easter egg chapters. I have never done it before, haha.

　　
　
(End of this chapter)