Metal Ranger of the Endless Plane

The SS-N-21 Sampson subsonic cruise missile, nicknamed the Tomahawk subsonic cruise missile, entered service a year later than the Tomahawk cruise missile of Meka, but the indicators are similar.

This type of missile has multiple models of land-based, air-based, and sea-based. In other words, the body itself can be launched from a corresponding missile vehicle on the ground, or from an aircraft, and finally from a ship.

Of course, each version will be adapted to the corresponding platform.

RK-55 is its land-based model and the first model. The empty base is Kh-55.

Among them, the power system of the land-based version and the submarine-launched version is mainly composed of a R95-300 turbofan engine to provide cruising power, and before reaching the cruising attitude, there is another solid fuel rocket booster installed at the bottom. supply.

Simply put, it's like a rocket extended-range projectile, when it is fired from the barrel, the power it relies on is the same as other ammunition, which is the combustion-to-detonation of the propellant behind the warhead.

But after launching, the engine in the rocket's extended-range missile ignites to provide additional endurance power.

Sampson’s submarine-launched cruise missile is similar. When launched from a launch tube or even a torpedo tube, it relies on the power of a solid-fuel rocket booster. After all, it is below the water surface and the speed is low, so solid fuel rockets are the best choice.

After being hit at a certain height in the air and reaching a certain speed, the main turbofan engine of the missile body works. Although the engine commonly used in this kind of aircraft cannot provide too high a speed, its fuel consumption is much lower than that of a rocket engine.

In the case of the same fuel volume or mass, the use of turbofan engines will make the projectile fly much longer than the continued use of rocket engines. The manifestation is that the range is greatly increased.

Of course, there are a series of other reference factors to choose cruise missile or ballistic missile. There are even political factors, but that is too complicated and has nothing to do with Lu Yuan, and he doesn't care much.

The biggest difference between cruise missiles and ballistic missiles is their flight trajectory. As the name suggests, a ballistic missile has a ballistic trajectory.

Basically, its rocket engine can fly with a powerful brick, forcibly pushing the projectile into thin air or even outer space, and then the projectile falls rapidly in a free-falling arc, hitting the ground target.

When it enters the atmosphere again, it has actually completed all its aiming behaviors, and only finally accelerating towards the target under the action of gravitational acceleration. At the end, the landing speed of the warhead can easily reach twenty-five or six times the speed of sound, that is, Mach 25 or Mach 26.

Therefore, intercepting such missiles is relatively difficult and costly.

Relatively speaking, the power of cruise missiles in the mid-to-rear process comes from turbofan engines, which are commonly used in civil airliners and third- and fourth-generation fighter jets.

For example, the Gulfstream G550 that Lu Yuan rode before was equipped with two Rolls-Royce BR700 turbofan engines.

And his F15C is equipped with two Pratt & Whitney F100-PW-220E turbofan engines.

The difference between the two is that the former has a larger bypass ratio, between 4.5 and 4.7, while the latter is less than 1, only 0.71.

The improved version of the latter has a bypass ratio of only 0.36, but it is a pity that the one in Lu Yuan's hand has not been replaced with an improved version.

In the early turbojet engine, after the air enters the engine from the intake duct, it will first be strongly compressed by the high-speed compressor. The reason for the compression is that the oxygen content in the outside air is not enough to support the violent combustion inside.

High-density and high-pressure gas enters the combustion chamber, mixes with fuel, burns violently, and then produces a jet with a higher temperature and a higher pressure. The turbine is impacted by the jet and rotates at a high speed through the shaft, thereby driving the previous compressor to rotate.

Finally, the jet exits at a high speed from the nozzle, generating a strong reverse thrust, driving the aircraft to fly at high speed.

The principle of a turbofan engine is basically similar to that of a turbojet engine. The biggest difference is that the turbofan engine is equipped with a huge intake fan in front of the compressor. In addition to assisting in the compression of air, this large fan can also act as a propeller.

Therefore, the fuel efficiency of the turbofan engine can be much higher, and the endurance time is also longer.

The turbofan engine has two air passages, the center one is called the inner duct, and the outer one is called the outer duct. When the engine is running, the ratio of the air flow between the outer duct and the inner duct is called the bypass ratio.

The larger the bypass ratio, the more fuel-efficient and the better the economic benefits.

Turbofan engines with large bypass ratios are more suitable for subsonic passenger aircraft. If fighter jets are used, such huge fans will undoubtedly bring fatal resistance at supersonic speeds.

Fighters generally use turbofan engines with a bypass ratio of less than 1, which brings less resistance and greater thrust.

But even so, if you want to achieve supersonic flight, you need to get higher thrust. For higher thrust, it is necessary to further increase the temperature of the combustion chamber, so that the energy of the heat flow jetted back is higher, so the thrust in turn is greater.

However, due to material limitations, turbine structures are generally difficult to withstand such high temperatures.

So the engine engineers simply added an afterburner behind the turbine, called afterburner in English. The name is more intuitive, after, behind, after so and so, burner, burner, burning person or thing.

In total, it burns again after burning, so it is also translated as afterburner.

In fact, it is equivalent to adding another combustion behind the main body of the turbofan engine. After this second combustion, the gas temperature can be increased again, thereby increasing the jet energy, and thus the thrust.

But because the air in the afterburner has been used by the previous combustion chamber, the oxygen content in it is not high. In this case, the fuel is injected for combustion, the efficiency is very low, and the fuel consumption is very huge.

When fighters are fully powered on, most of them will run out of fuel in less than ten minutes. Therefore, the afterburner is generally only opened for specific needs, such as taking off from an aircraft carrier, or fighting with enemy aircraft, and so on.

Returning to the cruise missile, Lu Yuan looked at the R95-300 turbofan engine used in the Sampson cruise missile, and felt that the bypass ratio was close to 1. In fact, the engine bypass ratio used by Meka's Tomahawk is really 1.

This is probably why a cruise missile with a length of less than 9 meters, a maximum projectile diameter of only half a meter, and a weight of less than two tons can have a range of up to 3,000 kilometers.

It is important to know that medium-range ballistic missiles with a range of about 3,000 kilometers, such as the former Soviet R-14, have a body length of nearly 25 meters, a maximum diameter of 2.4, 2.5 meters, and a take-off mass of 86, 87 tons.

For Lu Yuan, compared to ballistic missiles that use rocket engines throughout the course, the rocket boosters and turbofan engines used in cruise missiles are all devices he has a certain technical reserve. Maintenance, repair and even improvement are more convenient. .

What this thing brought to Lu Yuan was not only a complete set of cruise missile launch technology, but also the wing device on the missile body, which could also provide him with a lot of room for improvement in some of the weapons he was developing.

In addition, the connection technology of rocket booster and turbofan engine, inertial navigation technology, terrain contour matching technology, etc., all provide Luyuan with accumulation from scratch.