Chapter 589 Air-to-Air Missile (2)

Missile and rocket launches have been very dangerous for a long time. For example, due to the technical limitations of the time, the fuel used in early missiles and rockets was highly corrosive and extremely easy to burn and explode. Fearful accidents could occur if you were not careful. Even in later times, the fuel filling process of rockets and missiles is no joke.

During World War II, Germany's ME163 "Comet" interceptor, which used rocket engines, had frequent accidents. Unlike ordinary fighters, once the fuel tank leaked, the pilots in the cockpit near the fuel tank would be dissolved by the highly corrosive and toxic fuel! More Comet aircraft were lost due to fuel explosions than those shot down by the enemy.

Therefore, Yannick did not like liquid fuel from the bottom of his heart. "How is the research on solid propellants going?" Liquid fuel accidents occurred frequently, and the German army in World War II wanted to switch to solid fuel, but failed to do so because the war ended.

The earliest solid propellant was black gunpowder, one of the four great inventions of ancient China. As early as the beginning of the Tang Dynasty, around 682 AD, the recipe for black powder was included in the book Dan Jing written by alchemist Sun Simiao. It uses 15% charcoal as a combustion agent and 75% potassium nitrate as an oxidant. 10% sulfur is both a combustion agent and has the function of bonding charcoal and potassium nitrate.

In 975 AD, rockets using black powder were used as a weapon in war. In the 13th century, this type of rocket was introduced to Arab countries and later to Europe.

However, black powder has low energy and poor strength, and cannot be made into larger powder columns. When it burns, it generates a lot of smoke and solid residue. Solid rockets using black powder have a short range and low lethality. It is difficult to find black powder on modern missiles and rockets.

With the development of industry and science and technology, various solid propellants have sprung up like mushrooms after rain.

There are many materials that can become propellants. Any material that can undergo continuous combustion independent of external forces in the absence of external oxidants and can produce a large number of high-temperature gas molecules or solid jets during combustion has this potential. Generally speaking, combustion is a violent, rapidly exothermic redox reaction, so the propellant itself must contain both an oxidant and a combustion agent that acts as a reducing agent.

Propellants in which both the oxidant and the combustion agent are solid are called solid propellants. They are made into geometric shapes that meet the design requirements and cast or filled in a container with one end open. When ignited, the chemical energy of the propellant is converted into the thermal energy of the combustion gas, and when passing through the engine nozzle, it is partially converted into kinetic energy to form thrust.

Dr. Kramer said respectfully. "Composite solid propellants are still under development, and if it is fast, it will be successfully developed within a year."

In fact, solid propellants are ready-made, which is the smokeless gunpowder used in bullets and shells, that is, nitrocellulose.

Nitrocellulose is a fibrous substance that is difficult to make into a fixed-shaped projectile charge. People use viscous nitroglycerin as a plasticizer and mix it with nitrocellulose to form a double-base propellant. For a long period of time, double-base propellants have been the main raw materials for solid rocket engines.

Both nitrocellulose and nitroglycerin contain both oxidant and fuel components. Nitrocellulose is a bit fuel-rich (more fuel components), while nitroglycerin is a bit oxygen-rich (more oxidant components).

Originally, the combination of the two was ideal. However, with the increasing requirements for engine performance, the specific impulse that this classic combination can produce has gradually failed to meet the needs (specific impulse is an important physical quantity that describes the performance of a rocket engine, which is defined as the change in momentum that can be brought about by a unit weight of propellant. For the same weight of fuel, the higher the specific impulse, the greater the momentum that can be provided.)

After hesitating for a while, Dr. Kramer added. "But even this solid propellant is still inferior to liquid propellant in performance. While we are developing solid propellants, we are also working hard to improve the long-term storage technology of liquid propellants."

Liquid propellants have high thrust, strong load capacity, and are relatively simple in technology. Therefore, early ballistic missiles were generally liquid. But the inherent disadvantage of liquid missiles is that they cannot be stored for a long time, and the transportation process is relatively dangerous, and they will explode with a slight bump. With the breakthrough of long-term storage technology of liquid fuel, the fuel can be stored for many years after filling, so there is no need to fill fuel before launch.

The advantage of solid missiles is that they are flexible and maneuverable, but the disadvantage is that they have poor throwing ability because solid fuel has a low specific impulse. The price of solid rockets is high, large solid rockets are difficult to develop, and solid fuels have aging problems after long-term storage of rockets, and detection is very difficult.

In general, liquid missiles are suitable for when the technical level is not up to standard, and use lower technical difficulty to achieve higher technical indicators. Therefore, they are mostly used in early ballistic missiles, such as V2, Scud, etc. At the same time, they are also used for long-range missiles and intercontinental missiles that require relatively high throwing ability. The advantage of solid missiles is that they react quickly, so they are often used for mobile missiles and tactical short-range missiles.

Yannick sighed helplessly. "When using liquid fuel, you must pay attention to safety, and you must not be careless." Even if he uses the knowledge of later generations to promote the development of science and technology, it is impossible to leap twenty or thirty years at once, and he still has to proceed step by step.

After giving some instructions, we talked about the guidance mode of air-to-air missiles. The guidance method of this X-4 air-to-air missile is different from the infrared/radar guidance method of modern air-to-air missiles. It is guided by the pilot visually and controlled manually. However, for single-seat fighters such as BF-109 and FW-190, it is difficult for the pilot to control the aircraft and the missile at the same time. Therefore, the X-4 can only be deployed on multi-seat aircraft.

There are four large, X-shaped swept wings in the middle and rear of the X-4 missile body. Two of the wings have a wire release barrel at the top. The original design was to store 5,500 meters of copper thin wire in the barrel, but now it has been changed to optical fiber.

The other end of the wire is connected to the controller on the aircraft. During combat, the pilot remotely controls the pitch and yaw of the missile like operating a game controller to make it fly to the target. The maximum flight speed of the missile is 1,152 kilometers per hour, and the attack distance is between 1,500 and 2,500 meters. This is beyond the effective firepower range of the heavy machine gun, which is enough.

The missile in the original time and space has three detonation methods: one is to trigger the fuze; the second is to manually detonate it by the pilot; the third is the very advanced sound proximity fuze called "Kranich" at that time.

Because Germany did not develop the radio proximity fuze at that time, it could only use the sound proximity fuze instead.

The sound proximity fuze is activated by the Doppler frequency shift principle. The German army set its frequency to 200 Hz, which is the roar of the B-17 bomber engine. The fuze activation distance is about 40 meters and the starting distance is 7 meters. As long as the pilot guides the missile to the vicinity of the aircraft, it can be blown up, which is very effective.

Now that the German army is equipped with radio proximity fuzes, there is no need for this kind of sound proximity fuze.

Yannick briefly described the principle of infrared/radar guidance to Dr. Kramer, and Dr. Kramer was greatly inspired and said that he would start research and development immediately.

However, even if the research and development is successful in a short period of time, Yannick has no intention of putting infrared/radar air-to-air missiles into this war.

The first generation of infrared air-to-air missiles were typically the US AIM-9B "Sidewinder" and the Russian K-13. The first generation of radar air-to-air missiles were typically the US "Sparrow 1" air-to-air missile.

The first generation of air-to-air missiles had relatively poor attack capabilities, only slightly stronger than aircraft guns. At that time, a certain country was saying that "missiles were not as good as artillery shells, and they still had to rely on bayonets in the air."

In the 1960s, the second generation of air-to-air missiles began to prepare for the troops. Among them, the representative products of infrared air-to-air missiles include the US AIM-9D "Sidewinder", the French Matra R530, and the Russian R-60T. The representative products of radar-guided air-to-air missiles include the US "Sparrow 3A" (AIM-7E) missile and the British "Flame" missile.

Due to the poor reliability of the missile system, the US Air Force launched a total of 589 Sparrow 3 missiles in the Vietnam battlefield, only 55 of which hit the target, with a success rate of only 10%. At the same time, only half of the missiles could be used in combat.

In view of this, Yannick felt that it would have to be developed to the end of the second generation before it could be put into service in batches.

As for this war, this X-4 missile is enough. Its production process is simple, and unskilled workers can quickly become competent after simple training. Even in the case of extreme scarcity of resources in Germany in the late stage of World War II, the Ruhr Blackweed Factory produced 1,300 missiles in half a year.

Then after visiting surface-to-air missiles, air-to-ship missiles, anti-radiation missiles, etc., Yannick left the missile research and development center and returned to the palace.