Transmigrated as the Crown Prince

Although nuclear submarines are not expected in the short term, Yannick is not disappointed.

After all, in the 21st century a few decades later, not every country will have access to nuclear submarines. For many countries, there are insurmountable technical and financial difficulties in building nuclear-powered submarines. Therefore, while nuclear-powered submarines are being vigorously developed, conventional-powered submarines have not withdrawn from the stage of history. Moreover, conventionally powered submarines are more suitable for operations in offshore and shallow waters than nuclear submarines.

However, there is a big flaw in conventional powered submarines, which is that they cannot sail underwater for a long time because the battery capacity installed on the boat is limited and they must often float to the surface to "breathe", that is, use the diesel engine to charge the battery in the snorkel state. , so it is easy to be discovered by the enemy, and the noise made by the diesel engine when charging the battery is also easily detected by sonar and other underwater acoustic equipment. As a result, the submarine's exposure rate is greatly increased, and both the concealment of the attack and its own survivability are greatly affected.

In order to solve this problem, various countries have made long-term exploration and efforts. The development of various AIP power devices has been successful and has begun to enter the practical stage.

The so-called AIP is the English abbreviation of "Air Independent Propulsion Device".

Since the AIP power unit does not require oxygen to operate normally, installing it on a submarine can significantly improve the submarine's underwater endurance, increasing its underwater latency to 2-3 weeks, significantly reducing the submarine's exposure during cruise Rate. In this way, the bottleneck that has always affected the combat effectiveness of conventionally powered submarines has finally been resolved. Some people vividly compare a conventional submarine equipped with an AIP system to a "green nuclear submarine," which means that it has a large cruising power comparable to that of a nuclear submarine, but does not have the potential dangers and high costs of a nuclear submarine.

As early as before and after World War II, countries such as the Soviet Union and Germany had already been involved in the research of AIP power devices.

In 1935, the 18th Central Design Bureau of the Soviet Union proposed using the AIP system on submarines and tested it on the M-92 submarine, obtaining a large amount of test data. However, the technology was not yet mature at that time, and designers proposed air-independent technology only as an experimental subject.

During World War II, the German Walter Company experimented with using compressed hydrogen peroxide in submarines as a source of oxygen for diesel engines underwater. People who have studied chemistry know that hydrogen peroxide can decompose into oxygen and water. When the submarine is running underwater, the hydrogen peroxide is heated by the thermal energy of the diesel engine, and then oxygen is produced for use by the diesel engine. Later, Germany built a small number of these AIP submarines.

But Yanik doesn't like hydrogen peroxide because it is extremely unstable when it is converted into oxygen! In 2000, the Russian nuclear submarine "Kursk" suffered a disaster in history due to the leakage of hydrogen peroxide inside the training torpedo, which instantly exploded and caused a fire. The high temperature caused seven torpedoes equipped with real warheads to explode. The largest nuclear submarine sinking disaster, all 118 officers and soldiers on board were killed.

In later generations, there are three practical AIP solutions: closed cycle diesel engine, Stirling engine, and fuel cell.

The fuel cell technology is impossible in this era; using liquid oxygen or hydrogen peroxide is too dangerous. And it was not until 1993 that Germany successfully tested a 250-kilowatt closed-cycle diesel engine system on the retired 205-class submarine U-1. Yannick doesn't think he can make German technology leapfrog half a century at once; therefore, the safest way with current technology is to use a Stirling engine.

"General Dönitz, have you heard of the Stirling engine?" Yannick asked.

Dönitz nodded. "Are you talking about the Stirling engine invented by Englishman Robert Stirling?"

"right."

The 17th and 18th centuries were a time of great genius. There is a joke that in Paris, one copper can buy three geniuses.

Watt added a speed regulator to the steam engine, and mankind entered the steam age, followed by trains and ships. However, this steam engine consumed too much coal. At that time, some people believed that if hot gas was used instead of steam, the heat loss caused by condensation of steam could be avoided.

Based on this idea, British scientist Robert Stirling invented an external combustion closed-cycle hot air machine in 1816, the "Stirling Engine". The Stirling engine uses the working medium (hydrogen or helium) in the cylinder to output power through a cycle of cooling, compression, heat absorption, and expansion, so it is also called a hot gas engine.

It’s just that there was a lack of good heat-resistant materials at that time, and the French engineer Nicolas Leonard Sadi Carnot had not yet proposed the Carnot cycle. People’s understanding of the performance of the hot gas engine was very limited. The efficiency and power of the machine were known. are all very low; after the mid-19th century, with the invention of high-efficiency internal combustion engines and the large-scale exploitation of oil, the development of Stirling engines stopped.

This Stirling cycle hot air engine does not emit exhaust gas and does not require other air except the original air in the combustion chamber. Therefore, it is also suitable for urban environments and outer space. It ensures that conventionally powered submarines can sail underwater for a long time without the need for The ideal solution for floating.

Dönitz was confused. "But Your Highness, we don't have the technical reserves in this area. If we want to use this technology on submarines, we have to start research from scratch. I'm afraid it will take several years."

"It won't take a few years, General Dönitz." A proud smile appeared on Yannick's face. "Soon we will have ready-made research results."

Dönitz couldn't help but be stunned. "Ready-made? Where is it?" I thought it was researched by His Highness's secret scientific research department, but unexpectedly His Highness mentioned another country.

"The Netherlands. Their Philips company has been developing the Stirling engine a few years ago. I heard that it was finally successfully developed not long ago." A company that makes light bulbs develops engines? I don't know what they were thinking, but this gave him an advantage.

Of course, this Stirling engine can only be regarded as a prototype, and Yannick is not prepared to become fat in one bite. He does not expect the current Stirling engine to provide hundreds of kilowatts of power like later generations. It only needs to provide a few Ten kilowatts of power is sufficient. In addition to supplying normal lighting, electronic equipment and living facilities on the boat, the remaining energy can be used to propel the submarine. It is enough for the submarine to maintain continuous navigation for half a month at an underwater speed of a few knots.

Dönitz said excitedly. "That's great. The next batch of 'Tiger Sharks' should be able to use this engine." After all, the most important thing is to allow the submarine to have the ability to sail underwater for a long time. Reducing the snorkel status is the most important thing. Can avoid danger more effectively.

Then the two talked about wolf pack tactics. "General Dönitz, what do you think are the shortcomings of the 'Wolf Pack Tactics'? Don't have any worries, just say it."

Dönitz hesitated and then spoke carefully. "Your Highness, there are some problems. The biggest problem is the ownership of command authority. Should the submarine commander at sea or the command on the shore give unified orders for operations? If the command on the shore gives unified orders for operations, it will be difficult to do so. If we adapt to the situation, we may deploy fighter jets; but if we leave full power to the submarine commander at sea, once the enemy masters the method of locating based on radio transmission signals, our submarine's location will be easily exposed."

Yannick knew that Dönitz's worries were not groundless. British experts from the original time and space carefully studied the "wolf pack" tactics of German submarines and believed that if they could capture the signal sent by the tracking submarine and then use the signal to determine the submarine's position, The aircraft can carry out a quick and effective attack, making it impossible for the "wolf pack" to attack. British scientists have developed a small high-frequency directional detector that can accurately measure the position of a tracking submarine using the azimuth data measured by several instruments.

Coupled with the fact that Britain and the United States sent a large number of destroyers and aircraft for escort, the "wolf pack" that was extremely arrogant at the beginning turned into a "sheep pack" that was unable to fight back.