According to the "South China Morning Post" report, experts in well-known domestic academic journals published a paper saying that the problem of ballistic deviation when the electromagnetic gun fires shells has been solved, and the current trajectory has been accurate and controllable, even in the absence of guidance, it can meet the dispersion range requirements, and the paper also revealed that this kind of shell that solves the trajectory deviation is an intelligent guided projectile!
This means that the rumored electromagnetic cannon is not only a real hammer, but also solves the problem of ballistic accuracy! Is it possible to put it on the agenda? The rumors of the US military's electromagnetic cannon have been dismounted in 2021, is it true?
China has solved the problem of electromagnetic artillery ballistics: guided artillery shells, Mach 5, altitude 15 kilometers
According to a paper published in the Transactions of China Electrotechnical Society by a team led by Lu Junyong of the Naval University of Engineering, the Chinese Navy tested an electromagnetic railgun that can launch shells at Mach 5 to an altitude of 15 kilometers, where the air is thin and the air pressure is only one-tenth of that of sea level.
This shell also has a pair of gliding wings, which indicates that this is a guided projectile that can fly to the target along a smooth gliding curve at this altitude, and hit the target after gliding for 3 minutes, and if the gliding glider is improved, the flight distance of this shell can even reach more than 130 kilometers according to the farthest gliding bomb flight distance at present.
But beyond everyone's expectations, the test results were declared unsuccessful, because the projectile did not follow the expected trajectory, neither the range nor the maximum launch height met the design indicators, which made the scientists involved in the test quite discouraged, an epoch-making weapon could have such a low-level mistake.
The team led by Lu Junyong quickly found the cause of the problem, which turned out to be the imbalance of air resistance caused by the projectile's stable rotation speed during flight, which caused the projectile to deviate from the designed trajectory during flight, which seriously affected the quality of the trajectory and caused the altitude and range to fail to meet the design indicators.
Isn't the rotation of the shell more stable? How can you deviate from the goal?
There are two kinds of artillery, smoothbore guns and rifled guns, such as mortars and main battle tank cannons (most of them are smoothbore guns), there is no rifling in the barrel of the smoothbore gun, and the shell is slid through the barrel during firing, so it is called a smoothbore gun.
The difference between the muzzle of a rifled gun and a smoothbore gun
Rifled guns should be very familiar to everyone, there is rifling in the barrel, the winding distance is relatively long, the copper bullet belt at the waist will be closely fitted with the rifling when the shell is fired, so as to rotate in the barrel along the winding distance, although the rifling in the barrel is not a few turns, but because the shell passes through the barrel at high speed, the speed of the shell is very high, such as the 100 mm rifled gun of the Type 59 tank, the muzzle velocity of the shell is 900 m / s, and the speed can reach 18,000 rpm, that is, 300 revolutions per second, isn't it terrifying?
Copper single belt of rifled artillery shells
The smoothbore gun has a very poor accuracy and a high hit rate for rifled guns, because the spinning bullet has a more stable trajectory when flying, and the tip can be guaranteed to be pointed forward before hitting the target, which is also more guaranteed for the penetration of the bullet (if it kills the human body, it is not as good as a tumbling and unstable bullet, so some bullets will open a gap in the warhead to destroy stability).
Compared with smoothbore guns, rifled guns also have the advantage of good sealing, most of the power of gunpowder gas can be transmitted to the bullet, and the range is longer, but the shells of rifled guns also have a problem, one is that when the firing angle is too large, the shell may land on the tail, because the shell is too stable, and it still maintains the attitude when it is discharged until it lands, so mortars with too large firing angles can only use smoothbore mode.
The other is the deflection current, which is affected by the rifling angle, when the rotating projectile flies along the trajectory, the direction deviation to the firing surface, that is, the deflection current, the deflection generated by the right-handed rifling is biased to the right side of the firing surface, and the deflection generated by the left-handed rifling is biased to the left. The artilleryman had to correct the deflection when setting the firing elements.
Judging from the paper published by the team led by Lu Junyong, the problem is caused by rotation, and it is still too fast to deviate, simply put, the shell rotates when fired! This is a problem, the topic of the paper is an electromagnetic railgun, the question is, is the electromagnetic gun also divided into smoothbore guns and rifled guns?
The answer is no! At present, there are three kinds according to the principle of electromagnetic guns, namely the railgun fired by using a conductive track, the coil gun launched by the coil and the reconnected cannon with a reconnected coil, the first kind of flat or shell with a buttle, because it needs to be fired on a conductive track with positive and negative electrodes, this kind of shell must not rotate when fired, because such conditions are not allowed in the barrel.
The chamber of the coil gun is round, but it needs to be made of magnetic conductive materials, which is most likely a composite material, so it is not suitable to engrave rifling to add a rotational moment to the shell, so the coil gun cannot rotate;
The reconnection cannon is even more difficult, because this kind of cannon is used to fire a sheet of conductive objects, but this structure is more likely to be used in electromagnetic catapults, and is more suitable for firing low-speed and heavy-duty loads, because coils can be connected in parallel to increase the "torque".
After analysis, it is known that all electromagnetic guns do not rotate when the projectile is fired, and the projectile can only rotate after the projectile flies out of the muzzle, and the method is also very simple, increase the angle of the tail fan fan at the tail of the shell, and then the scouring of the incoming air flow (or use a miniature rocket to push the rotation), the shell will rotate, this way will increase the stability of the shell, and the trajectory of the shell is more predictable.
RPG rotates after being disemboweled
However, according to the paper, the rotational speed of the shell was designed to be too large, the lateral roll was beyond expectations, and it also generated additional resistance, resulting in the trajectory and range could not meet the original design requirements.
Mach 7 200 km: Scare you to death with a shovel
The team led by Lu Junyong mentioned that the maximum velocity of the artillery shell is only Mach 5, but the data mentioned in the previous papers is Mach 7, and the range can reach about 200 kilometers, if the guided projectile described above, then a shell of several tens of kilograms is equivalent to a missile with a range of more than 200 kilometers.
For the air defense system of the general fleet, it is relatively safe to launch a strike 200 kilometers away, assuming that the two powers meet, one side is equipped with an electromagnetic railgun, and it comes with a three-minute rapid fire, if it is fired at an interval of 30 seconds, it can fire about 6 shells, if it is fired at an interval of 15 seconds, then it can fire 12 shells, and if it is fired at a salvo of two guns, it can launch 24 shells, think about it, a shell that arrives at a speed of Mach 7, the radar does not even have time to react and hits the target, However, the cost is only one knowing the price of the shell, and it instantly becomes an anti-ship missile when it is anti-ship, isn't it quite shocking?
China solved the orbital ablation problem, but the US military could not solve it and dismounted in 2021
The above introduced three kinds of electromagnetic guns, namely railguns, coil guns and reconnection guns, at present, the closest to practical is the railgun, that is, the simplest structure of two tracks plus a constrained shell of the railgun, the principle of physics to know, conductive objects in the left and right orbits in the super current of the magnetic field driven by high-speed drive.
The structure is simple to the point of "outrageous", but it is quite difficult to manufacture, the reason is very simple, you will understand by calculating, if you want to accelerate a 30-kilogram shell to Mach 7, then the electrical energy used is about 9.375e+7 joules, about 26 kilowatt-hours of electricity, assuming that the track length is 30 meters, the inlet velocity is zero, and the outlet velocity is 2.5 km/s, then the average power is 3,900,000KW, which is 3900MW.
Do you know what this means? Even if the efficiency of the railgun can reach 80%, there will be 18.7 megajoules of energy released in the barrel, which is almost 4.4 kilograms of TNT energy, simply put, most of it is the energy released by the arc generated when the armature of the butt is in contact with the track, at extreme high temperatures, the ablation and electrochemical action of the track will seriously corrode the track, under normal circumstances, if the "gun chamber" is not exploded at that time, it will also be burned after a maximum of dozens of shells are fired, the guide rail and the gun chamber will be burned and unusable.
The United States will be dismounted because this orbital ablation problem cannot be solved, so it will be dismounted in 2021! U.S. involvement in the development of electromagnetic guns has long been precedented, even as far back as the 1980s: when U.S. Army laboratories began theoretical research programs on railguns, and in 1990, the U.S. Army partnered with the University of Texas at Austin to establish the Institute of Advanced Technology (IAT), which focuses on research involving solid and hybrid armatures, orbital-armature interactions, and materials for electromagnetic emitters.
- In 2005, the U.S. Office of Naval Research (ONR) officially began the railgun program, with railguns from BAE Systems and General Atomics competing;
- In 2007, the first test launch of the electromagnetic rail gun (EMRG) was carried out, but it suffered from a problem of severe ablation of the rail, and after improving the rail, it has been tested about 300 times a year since 2008, and ONR said that BAE has a better firing rate and frequency.
- In December 2010, the U.S. Navy Surface Operations Center successfully completed the launch test of the 33 megajoule electromagnetic rail gun, and the muzzle velocity reached 2~2.5 km/s.
- On October 31, 2011, the U.S. Navy website reported that scientists at the Naval Research Laboratory (NRL) successfully completed the 1,000th test launch of the Electromagnetic Rail Gun (EMRG) project's laboratory-scale electromagnetic rail gun system.
After decades of research and development, General Atomics and BAE have come up with their own electromagnetic gun products, the muzzle velocity and muzzle kinetic energy and other key indicators are good, but there is only one problem that can not be solved, that is, the ablation problem of the barrel and the inner wall of the electromagnetic gun can not be solved, which leads to a very serious problem, the accuracy of the railgun in the design of more than a dozen rounds because of the ablation problem decreased, and it was completely scrapped after dozens of rounds.
In 2018, the budget for the electromagnetic gun was allocated to the RDT&E (Research, Development, Testing and Identification) funding project, and the original plan for ship testing was also delayed, and finally in 2021, the research and development of the electromagnetic gun in the new annual budget of the US military was cut, and in the budget for the 2022 fiscal year, the EMRG funds have disappeared, which means that the US Navy's electromagnetic gun project has officially come to an end!
So far, there is no sign of restarting the research of the US military, but Japan's electromagnetic guns are very active in cooperating with the US military, but in terms of the mainstream technology level of the global electromagnetic guns, the current Japanese research is still at the level of kindergartens.
China's electromagnetic cannon research started with the US military, responsible for the research and development of Xi'an Institute of Electronic Engineering (206 Research Institute) and China Electronics Technology Group Corporation (27 Research Institute), but due to China's relatively thin technical foundation, the progress is relatively slow, until 1990 to achieve the first launch of the 303EMG electromagnetic gun, the mass of the "shell" at that time was only 30 grams.
In May 2001, the Institute of Nonferrous Metals in Beijing undertook the research and development of high-temperature superconducting films, and China's electromagnetic cannon research began to accelerate. At the 13th International Conference on Electromagnetic Emission in Germany in May 2006, China produced 52 papers, second only to the 72 papers from the United States.
According to foreign satellite pictures, in 2011, China carried out a test launch of an electromagnetic cannon at the Baicheng Artillery Test Base in Inner Mongolia, the orbital length of the electromagnetic gun reached 33.5 meters, and the target was 12 pieces of concrete with a 60-degree inclination angle plus multi-layer homogeneous steel plate targets, and single concrete targets of different thicknesses, according to external network reports, 10-meter concrete targets and homogeneous steel plate targets were broken down.
In February 2018, a photo of the Type 072 II "Ocean Mountain" landing ship suddenly appeared on the Internet, with a fairly large cannon at the bow, the barrel wrapped in camouflage strips, divided into two sections, with a total length of 18.5 meters, 15 meters shorter than the electromagnetic gun tested in Baicheng, and the logistics support modules on the deck are also 3 fewer than the 6 released by the US military, but it is not sure whether some modules are in the cabin of the landing craft deck. The turret is somewhat similar to the traditional naval guns of the mainland, apparently this is an electromagnetic cannon, and it also looks like a very mature electromagnetic cannon.
According to online news, this electromagnetic gun test can accelerate a 25-kilogram shell to Mach 7.3 (2.48 km/s, another says 2575 m/s) and hit a target 250 kilometers away. This means that China has successfully miniaturized in the field of electromagnetic guns and has been tested on ships.
China is progressing so fast, is the problem of ablation so solved?
On November 10, 2022, the Journal of Huazhong University of Science and Technology Natural Science Edition published an article entitled "Research Status and Prospect of Insulating Supports for Electromagnetic Orbital Launchers", which briefly reviewed the causes, results and solutions of insulation and orbit damage:
- Causes: High-temperature ablation and impact associated with plasma armatures are the main causes of material damage;
- Results: The track material has poor ablation resistance or is prone to structural damage, and the matrix erosion, metal pollution and erosion damage caused by the C-shaped aluminum armature are damaged.
- Solution: The toughening technology of ceramic materials is the key to solving the insulation problem of plasma armature railgun; The composition and preparation process improvement technology of composite materials and surface spraying technology are effective means to solve the insulation problem of C-shaped aluminum armature railgun.
Chinese scientists have tested a large number of materials and demonstrated the ablation process in the barrel of different materials, and finally determined that a composite of alumina and silicon nitride with high toughness, high strength and excellent insulation performance with phase change toughening, whisker toughening or fiber toughening may become the insulating support material for armature railguns.
Some netizens will suspect that the flower grower may have leaked secrets, but in fact it will not, because these are all information or academic papers that can be found publicly on the Internet, and you can also go to inquire directly about the papers mentioned above, which are still free.
The paper published this time has solved the problem of deviation from the target during the flight of the shell, which can increase the shooting accuracy for unguided ordinary shells, and can reduce the number of adjustments to the attitude control during flight for guided shells, which greatly reduces the requirements for the control margin of the artillery projectile guidance system, and can reduce costs and improve the accuracy of hitting.
But more importantly, many netizens have complained about China's electromagnetic cannon, the reason is that it has not been equipped for a long time, from the paper published by the team led by Lu Junyong, we can also learn that the electromagnetic gun has been improving and improving, and it is also becoming more and more mature, friends who see it should celebrate, it is estimated that it will not be long before we can see the electromagnetic cannon on the 055 improved model.
Reference: https://www.scmp.com/news/china/science/article/3262607/chinas-rail-gun-sends-smart-bomb-stratosphere-hypersonic-speed-then-something-goes-wrong