Siheyuan: I eat melons while doing scientific research

Chapter 1186 Harmful
Gao Zhendong smiled and shook his head: "No, ELF is always there, regardless of whether the submarine is communicating via long waves. Although it is weak, it is still relatively easy to reach the detection limit for equipment of this size that can be carried by an aircraft."

???

Gao Zhendong's words made Zhu Gong stare with wide eyes, not to mention others. How come I don't know about this? I work on submarines. Although I am not responsible for the overall model, I still have some understanding of other subsystems. I have never heard of any submarine that is constantly launching ELF.

There has never been such a submarine in the past, there is none now, and there will be no such submarine in the planning, demonstration, or design in the future.

But he knew that Gao Zhendong must have discovered something he had not expected, or even that this was something the entire team had not considered.

"Commissioner Gao, can you explain it in detail?" Engineer Zhu immediately became interested.

Gao Zhendong nodded: "Engineer Zhu, as we all know, submarines are made of steel, and steel is not very resistant to corrosion in seawater. In order to protect the hull, cathodic protection measures are often applied, and this cathodic protection measure is not sacrificial anode protection, but impressed current protection, right?"

Gao Zhendong didn't know whether this matter was well known, but he knew that Zhu Gong must know it. Moreover, sacrificial anodes are not suitable for use here. The anti-corrosion cathodic protection measures for submarines generally use impressed current cathodic protection, which is to turn the hull into a cathode in the electrochemical principle to receive electrons, so that it will not be corroded.

When Zhu Gong heard this, he was dumbfounded. It was really difficult for him to answer this question. It was a violation of discipline! Whether he answered yes or no, it was inappropriate. However, he once again thoroughly experienced the other side of Gao Zhendong as a materials expert.

Seeing his look, Gao Zhendong probably understood his dilemma. He didn't wait for his answer, but continued to talk: "In this case, an electric current loop will be generated between the hull, seawater, and propeller. This is inevitable because this loop is the purpose of this protection method. Without it, there is no way to protect the hull. But this will bring a problem..."

Well, as expected, although Gao Zhendong hadn't finished explaining why, Zhu Gong had already realized that this problem was a congenital one.

"…The rotation of the propeller will cause the resistance of this circuit to change. The rotation of the propeller is periodic, and the periodic resistance change will cause the periodic change of the circuit current…"

There is no need to say what comes next. Anyone who has studied junior high school physics knows that alternating electric fields produce alternating magnetic fields, and ultimately produce electromagnetic waves. The frequency of this electromagnetic wave is highly positively correlated with the rotational speed of the propeller.

No wonder it is ELF, the electromagnetic waves generated by the propeller's rotation speed are just within the frequency range of ELF.

As for the rest, the comrades all understood without Gao Zhendong continuing to explain.

——ELF is used for communication because it has a low frequency and low attenuation, which means that aircraft can detect submarines at a longer distance.

Moreover, this thing is completely unaffected by weather, sea conditions, etc. Unless the submarine propeller stops completely, it will always be like a leech attached to the bones, tightly entangling the submarine.

Moreover, one advantage of ELF detection is that the means of detecting this type of signal is even more mature than sonar. The reason why it was not available before is because no one thought of that direction. Once it is thought of, it is actually easier to make targeted equipment than sonar.

Only then did Mr. Zhu realize what Gao Zhendong meant when he said at the beginning of the meeting: "I'm going to cause you trouble next."

Putting aside known troubles such as sonar and unsolvable troubles such as gravity gradient, all of them added together are not as troublesome as this one. The hull must be protected, and it is difficult to remove this protective measure. You must know that the submarine, this steel behemoth, can only survive in the sea for so long with the combined effect of multiple protective measures.

"How far can this method detect?" Engineer Zhu knew that compared to other methods that each had their own flaws, except for sonar and magnetic anomaly detectors, this thing caused the most trouble.

Exhaust gas is too targeted and has a narrow scope of application.

Infrared and laser are affected by diving depth and weather.

Wake currents are greatly affected by diving depth and sea conditions. It sounds like the technology of that unknown radar is quite difficult.

Gravity gradient and technical difficulties may not be used in anti-submarine warfare. He now understood that if Gao Zhendong could say "difficult" about this thing, it must be really difficult. As for why, is there any need to explain?

Gao Zhendong gave a number: "Based on current technical conditions, it is about 1 kilometer."

The number 1 kilometer is not small. It means that a patrol aircraft or anti-submarine ship can obtain a detection width of two kilometers, which is of great significance for patrol aircraft.

Even for anti-submarine ships that have various sonar-based submarine search methods, this thing is a very good supplement. After all, as long as the propeller keeps turning, it will always be firing.

"This..." Gao Zhendong laughed. "For this thing, if a submarine wants to fight it, it can only start with the detection distance. The detection distance of this thing is not very large, so it can be avoided. At the same time, timely shutdown when necessary is also a solution. Of course, the timing of shutdown is difficult to grasp, because the submarine has no idea when there will be a plane overhead. But unless the hull material is changed or the protection method is changed, there is no solution. In fact, in a word, in front of a fully armed anti-submarine patrol aircraft, a submarine has no chance except to hide at a great depth."

Otherwise, why did they build anti-submarine patrol aircraft so frantically after the conditions were met? Because this thing is easy to use!
The means by which anti-submarine patrol aircraft deal with submarines are far more than the magnetic anomaly detectors and densely packed sonar buoys on the belly that most people see in photos. These two items are actually used to hunt submarines after they are discovered. What really allows anti-submarine patrol aircraft to detect submarines over a large area is actually various wake detection methods with sufficient accuracy. However, this is a later story and it is impossible to talk about it here today.

Of course, the "fully armed" anti-submarine patrol aircraft that Gao Zhendong mentioned does not exist at present, including in the United States.

"Well, it seems that there is still a long way to go to resolve the underwater conflict."

However, the comrades engaged in anti-submarine operations were very happy. The idea proposed by Commissioner Gao was tricky and the angle was vicious, but the technology itself was not too difficult, and it was even easy to understand.

There is no need to go to Commissioner Gao for this matter later. You can just go to the Radar Institute, Communications Institute, Electronics Research Institute and other units and ask comrades to customize an ELF detection device. Once installed on the Be-6, you will have another powerful weapon. This thing can even be used together with the thermal wake thermal imager to become the earliest practical new submarine search equipment on the Be-6.

Given the diving depth and characteristics of current submarines, these two pieces of equipment alone are already a great threat to submarines. When all the equipment is gathered together and formed into a set, it will become what Commissioner Gao calls a "fully armed" anti-submarine patrol aircraft. Then we'll see which country's submarines dare to come in!

Those who often play games know that when a set of equipment is complete, there will be additional attribute bonuses.

When the meeting was adjourned, the leaders of the Defense Work Committee and the Navy called Gao Zhendong over.

"Comrade Zhendong, you have solved a big problem for us, but you have also brought us a big problem. The comrades working on anti-submarine warfare are happy, but the comrades working on submarines will have trouble sleeping. This has caused great harm to others."

The leader of the Defense Committee was half joking, but the comrade from the navy waved his hand and said, "Don't listen to his nonsense, Comrade Zhendong. We need the troubles you have found. It is much better for us to have the troubles found by our comrades and be prepared for them than for the enemy to secretly hold them in their hands and suddenly use them against us. Your anti-submarine methods today are really eye-opening for us. Even if we cannot solve them technically for the time being, we must prepare for them tactically and have a plan to deal with them."

Gao Zhendong smiled and said, "In fact, part of this is just my vision of future anti-submarine technology. In a short period of time, it will be difficult for both the enemy and us to realize this full set of technology."

The leader of the navy smiled and said, "It doesn't matter. We are prepared for a rainy day. We need to evolve our tactics and methods. When necessary, we also need to keep up with submarine technology. Maybe we can't do it now, but I believe we can do it one day!"
-
After giving a comprehensive reminder to the navy and submarine research comrades, Gao Zhendong woke up the next morning and saw a piece of news in the Daily News.

Finally, what was supposed to come has come. If he had seen this news with his own eyes in his previous life, he would probably be very happy.

But now seeing this news, Gao Zhendong is not so happy. The main reason is that the opponent is too weak and can no longer stimulate his dopamine.

That’s right, Zang San, the former leader who was lying on the ground playing the string instrument, finally couldn’t escape the fate he deserved.

——Dead!
It is said that the head of a country is really awesome. He can pluck a string longer than an ordinary person.

However, he was even worse off than Gao Zhendong had known in his previous life. He witnessed one farce after another on his own land with his own eyes. The problem he most wanted to solve was not only not solved, but it was even more serious than Gao Zhendong had known in his previous life and directly broke out.

So not only did this guy lie down even harder, but he also died faster than Gao Zhendong knew in his previous life, and he didn't even survive until the end of 63.

Gao Zhendong looked at the report in the newspaper, shook his head and sneered.

The first "third in the world" has completely fallen. Look at it, it's scattered here and there, blue and red. It won't be able to make a comeback in the next few decades.

Gao Zhendong put down the newspaper and came to the third factory in a happy mood. As soon as he entered the office, a comrade came to see him. It seemed that he was delayed by the two-day meeting of the Defense Working Committee.

The visitor was none other than a comrade from the Institute of Research and Development, who cheerfully stated his purpose as soon as he entered the door.

"Counselor Gao, we're here to see you again about the double pulse issue..."

At this time, you have to call him Senior Advisor to appear more friendly.

(End of this chapter)