The experimental No. 1 submarine, which was all exposed to the water, was even more unbearable to look at, and the staff quickly went up to tear off the shark skin that had been half-shed, and cleaned the hull, at this time, it looked a little more pleasing to the eye.

This busy work is almost evening, Li Rujin turned the data handed over by the captain, and carefully checked it, this time the data looked much more beautiful, which made Li Rujin very satisfied. The economic speed has exceeded 3 knots, reaching 3.6 knots, and the cruising speed has also increased a lot, reaching 10.2 knots, and the surprise is still in the escape speed, reaching a gratifying 27 knots, which is an unexpected breakthrough.

It seems that the shark skin and the five-bladed oars are still very powerful. Li Rujin returned to the office with the data satisfied, put the data together with the data collected before, and sat in the office and remembered her thoughts.

Now everything is waiting to see the performance of "change one", if "change one" performs well and the performance is stable, then this submarine can basically be finalized, thinking of "change one" Li Rujin seemed to think of something, and hurriedly walked out of the office and came to the dry dock.

The transformation of the "change one" is still in progress, and the original cylindrical bridge has disappeared and has been replaced by a newly designed streamlined bridge, with soft lines that look very aesthetically pleasing, and the smooth hull is in perfect harmony, fully reflecting the beauty of industrial aesthetics.

Li Rujin entered the power compartment of the submarine, and when he saw the equipment on the engine, Li Rujin showed a satisfied smile. The engine has been installed with the silencing technology of the Imperial Capital Research Institute, and when it is time to transform the "change one", Li Rujin asked the military research and development personnel of the research center whether the sound reduction technology can be applied to the "change one" engine.

Military researchers quickly set up a research and development team, began to study how to apply this set of technology to the engine, the military research and development personnel have a wealth of experience in this area, in the manufacture of the hull, also developed the submarine sound reduction technology, and achieved certain results.

Compared with the technology of the Imperial Capital Research Institute, their technology is backward, but they have accumulated rich experience, and after thoroughly understanding the technology of the Imperial Capital Research Institute, they quickly developed a reasonable plan and applied the sound attenuation technology to the engine.

The staff told Li Rujin about this matter, but he was busy with the shark skin and the five-bladed oar, so he forgot about it, and knew that he only remembered it today and came to take a look. The engine of the "change one" is noticeably fatter than the engines on other submarines.

This circle is the muffler plate, the muffler version is mainly attached to the cylinder wall of the engine cylinder, the noise source of the diesel engine is mainly the diesel engine when the work, the sound of the mixed gas burning violently in the cylinder. Therefore, the cylinder part is the main battlefield of sound muffling.

In addition, the R&D personnel also installed a silencing version on the wall of the power compartment as a secondary silencing to minimize the noise transmission of the engine and eliminate the noise at the source.

According to the R&D personnel, the effect seems to be very good, but Li Rujin has not really seen it. Li Rujin wanted the staff to start the engine and let him see the effect, and after a while, Li Rujin dispelled this idea, don't trouble the staff because of his willfulness.

These days, the staff are very hard, the construction period is short, and the quality must be guaranteed, and they are all tired and about to get out of shape, Li Rujin really can't bear to cause trouble to them. Anyway, in a few days, the "change one" will be tested, and I don't care about the time of these few days.

During this period, "Experiment 1" conducted another shark-free skin test, and obtained a set of comparative data, which proved that the shark skin did improve the speed of the submarine a lot, but the highest speed increase was the five-bladed oar.

Without the shark skin, Experiment 1 also had an economic speed of 3.3 knots, only 0.3 knots lower than when the shark skin was present, and nearly one knots faster than the three-bladed oar.

This speed increase is terrifying, and the magnitude has exceeded 40%, which is simply an exaggerated figure.

Li Rujin began to think about whether it was possible to consider removing the shark skin from the submarine, the shark skin has two main functions on the submarine, first, to reduce the resistance of the whirlpool, the protrusions on the shark skin can break up the tiny whirlpool formed on the side of the hull when the submarine is sailing, and reduce energy consumption.

Second, it is to prevent marine organisms from parasitic on the hull, especially shellfish, for shellfish organisms, the hull of the submarine is a natural parasitic place, under normal circumstances, the sailing speed of the submarine is very slow, and the smooth hull is easy to parasitize shellfish, and it is a free ticket, so that the submarine can travel around with them.

But for submarines, it is a potential threat, shellfish secretions have a great corrosion of the submarine's hull, forming one pit after another on the hull, reducing the pressure resistance of the hull.

In addition, shellfish are attached to the hull of the boat, forming resistance during the navigation of the submarine and increasing the energy consumption of the submarine, it seems that the shark skin cannot be removed. But the current shark skin technology is only beginning to develop, not only the cost is high, but also not durable, or wait for the shark skin technology to mature in the application of submarines, now do not consider.

After several days of waiting, the renovation project of "Change One" was finally over, and after several no-load runs on land, no problems were found, and it was finally decided to start testing at sea.

The Zhoushan Shipyard has accumulated rich experience in testing submarines into the sea, and is familiar with the road, and the test of "changing one" is very successful. Li Rujin held a stack of test data and smiled proudly.

The underwater economic speed reached 4.2 knots, the cruising speed was 13.1 knots, and the escape speed also increased to a certain extent, reaching 28 knots, but the escape time was reduced, only less than 40 minutes.

The most surprising thing about Li Rujin is that when the submarine is sailing underwater at an economic speed, the noise is below 60 decibels, and when cruising, it is only 75 decibels, and only when the escape speed is the decibel value exceeds the ocean background noise, reaching more than 100 decibels.

Even when the floating engine of the submarine charges the battery, the noise decibels are only 70 decibels, and the sound reduction technology of the imperial capital is simply too powerful! 70 decibels, what a surprising data, Li Rujin can't wait to kiss two mouths on this data to express his joy.

In the following month, Li Rujin launched a non-stop test, and the oxygen candle was also applied in the continuous test, and the data obtained made Li Rujin almost crazy.

The underwater self-sustaining power has reached more than three days, and the endurance of the submarine has exceeded 4,000 nautical miles, but the problem has also arisen, the original supply of the submarine is not enough, and the load ratio of the submarine must be redone.

But all this is not so important, in his heart, Li Rujin can already be sure that this submarine has been successfully developed and can be finalized and produced!