The barrel of a rail gun consists of two parallel guide rails about 6 meters long, which are connected by a smooth rotor. The current flows from one track, through the rotor, and then back to the other track. This loop generates a magnetic field to push the rotor, and then push the shell in front of the rotor to fly out of orbit.
Ordinary naval guns have a range of only 20 kilometers, and their accuracy is very poor. Although cruise missiles have an effective range of more than 300 kilometers, they are expensive, and a ship can only carry up to 70 pieces. Because it can't be loaded and unloaded at sea, it must return to the port when replenishing. Rail guns have many advantages, such as long range, low cost, convenient transportation and complete supporting facilities, and are highly anticipated by the US Department of Defense. The railgun is even regarded by the US Army as a candidate technical solution for the main battle weapon of the army chariot after 2020.
However, the technical research of electromagnetic launch may continue for more than 20 years, because no warship can generate and store the electric energy needed for launch. In the past, 90% of the energy on the destroyer was used to supply the propulsion system. In addition, the challenges include: high-precision control technology to ensure accurate hitting of the target, and the ability of the projectile to withstand huge acceleration. Because the distance from the target is more than 300 kilometers, this gun can't aim like an ordinary barrel and needs pneumatic correction. When the shell is in the air, its running direction must be corrected by the instructions of the satellite. At the same time, the acceleration of the projectile when it leaves the cabin will reach 45,000 times that of the earth's gravity, and the electronic equipment carried on the projectile must bear this acceleration. In addition, it is difficult to make the rotor move at high speed in the barrel.
At present, the US Navy is cooperating with the British Ministry of Defence to develop this kind of rail gun. They are going to convert the destroyer into an ultra-long machine gun, which can fire 12 rounds of this cheap shell in one minute. In 2003, a factory in Corkubri, England, made a sample of this kind of rail gun with the ratio of 1∶8, and launched a shell flying stably at the speed of 6 times the speed of sound in the experiment. However, according to Colonel Roger mcginnis of the US Naval Ocean Systems Command, American railguns will not be delivered until 20 15 years at the earliest.
After years of efforts, the science and technology used in rail guns have made great progress, which can be used in military applications and laid a solid foundation for the research of rail gun combat system.
First of all, the US Department of Defense decided to study the DDG- 1000 integrated power system ship, which opened the door for the research of a new generation of power weapon systems, including rail guns. Because the power required by the rail gun depends on the speed at which the projectile is launched. The rated electric power of the integrated power system ship is 80 MW, and it has enough power to maintain 15-30 MW rail guns to fire projectiles at a speed of 6- 12 rounds per minute. At the same time, the rail gun does not need high-energy explosives such as gunpowder, which improves the safety of the ship and reduces the logistics support cost. Second, the development of precision guidance technology has promoted the development of rail guns. The US military has increasingly applied guidance, navigation and control system technology, which provides opportunities for developing smaller, more deadly and cheaper projectiles. This trend only benefits from the development of low-cost and high-speed rail gun bullets. The third is the extension of barrel life. The Institute of Advanced Technology of the University of Texas has made great progress in barrel life technology for the US Army. The contact surface between armature and guide rail is affected by two kinds of wear phenomena, which limit the life of barrel: one is planing, the other is translation. At present, American technicians fully understand the physical causes of high-speed taxiing and find materials to solve this problem. When the armature changes from metal-to-metal contact to arc contact at the muzzle, the corresponding plasma will destroy the orbit. At present, the High-tech College of the University of Texas has demonstrated a successful way to deal with translation problems.
In 200 1 and 200 1 1 year, the US Naval Institute of Advanced Technology obtained the main performance parameters of the new electromagnetic railgun system through parameter research and modeling activities: the railgun can be installed on surface ships, the weight of which is equivalent to 155 mm, the initial kinetic energy can be 63 MJ, and the initial speed is 2,500m. It takes only 6 minutes for a high-speed projectile to reach the target 200 nautical miles away, and it can hit the target with kinetic energy at Mach 5. The initial kinetic energy and velocity required by pulse forming network (PFN) to generate projectiles are also estimated.
With the deepening of the research on DDG- 1000 initiated by the US Navy, the US Navy plans to install electromagnetic guns on this platform, and awarded a contract to the weapon system department of BAE Systems Company in 2003 to conduct a six-month research on integrating rail guns into new destroyers. After research, BAE Systems believes that DDG- 1000 integrated power system ship with power of 8 1 MW can provide enough power for two railguns. When the ship is sailing at the speed of 10- 18 knots, the rail gun can fire 10- 12 shells per minute. The weight and volume of rail guns are suitable for installation on surface ships. At present, the main engineering problem facing the synthesis work is only the heat energy management generated by the rail gun.
A major milestone in the history of rail gun research is that the US Navy successfully completed the demonstration and verification test of how the 90 mm electromagnetic gun fired hypersonic ammunition at sea in Kirkbury County, Scotland in April 2003. The test was jointly completed by the US Naval Sea Systems Command and the electromagnetic gun factory of the British company * * *. The system used in the test is a prototype, the size is 1/8 of the future prototype, but the initial velocity of the launched projectile exceeds 2500m/s (the specific velocity is still confidential). Many senior US Navy officials, including Admiral Robert Knight, commander of the US Navy Fleet, and Major General Jay Cohen, director of the Naval Research Bureau, participated in this promising technical verification test. This test is a key step in naval firepower reform and changing the role of a new generation of naval guns and naval surface combat ships.
The U.S. Naval Maritime Systems Command submitted the test results in Curca Bury to the electromagnetic gun technology research group of the U.S. Naval Maritime Research Advisory Committee. The group published an assessment report in February 2004. The report believes that the electromagnetic gun is a potential transformation weapon, and suggests that the navy start a risk reduction research plan to ensure that this weapon is suitable for future destroyer plans. The team also believes that the electromagnetic gun is a revolutionary electromagnetic gun combat system, which can attack targets beyond 200 nautical miles, and has the advantages of increasing ammunition reserves, improving development, reducing costs and logistics support requirements. It was a big mistake to give up this research.
On June 65438+1October 65438+June, 2007, the United States Naval Research Office (ONR) held a delivery ceremony of a new type of electromagnetic device at the Dargren branch of the Virginia Naval Surface Warfare Center. Instead of cutting the ribbon with scissors, the US Navy broke the routine and fired 1 high-speed shells through the ribbon with a 90mm experimental electromagnetic gun. The initial kinetic energy of this kind of shell at the muzzle reaches 7.4 MJ, and the initial velocity reaches 2 146 m/s ... But more significantly, the delivery of this new type of electromagnetic gun once again proves that the US Navy is full of confidence in high-energy rail guns. The U.S. Navy will use this kind of rail gun as a modification weapon scheme, and launch high-speed projectiles to accurately strike long-range targets, thus changing the U.S. Navy's maritime attack actions.
The delivery of the launch test device in Dahlgren Division is only the beginning. The goal of the US Navy is to develop a tactical system that can continuously fire precision ammunition from warships more than 300 nautical miles from the coast. Although this kind of ammunition contains little or no high explosive material, it can destroy the target through the high-speed collision of projectiles. Rail guns overcome the limitations of conventional guns, such as short range, short flight time and limited lethality. Because electromagnetic shells have no explosive materials, there is no need to produce, transport, handle and store explosives. In addition, the ultra-long-range, extremely short flight time and high lethality greatly enhance the attack power of the US Navy in future long-range operations. By using extremely high current to generate strong electromagnetic force, the future rail guns of the US Navy can launch projectiles with a speed exceeding Mach 7. The projectile first quickly enters the outer atmospheric space and flies without resistance, and then re-enters the atmosphere and hits the target at a speed above Mach 5.
The US Naval Research Office strives to push the research of railguns to the military stage, and plans to equip troops in 2020-25.
In August 2005, the US Navy launched a project called "Innovative Naval Prototype", hoping to acquire relatively mature technology through investment in this transitional project, so as to transfer to the comprehensive research and development of rail guns in the next four to eight years. The project of "innovative naval prototype" is much more "wonderful" than traditional weapons and equipment, and the risk is high. It also fundamentally deviates from the established requirements and operational concepts. Therefore, it is impossible to carry out this research without the approval of the senior leadership of the US Navy.
The US Navy plans to invest $270 million in the "Innovative Naval Prototype" project, which mainly solves four technical problems: launcher, projectile, pulse forming network and ship synthesis. The main research work of the US Naval Research Office in the first phase of the project focused on launchers and projectiles. The research focuses on the advanced sealed launcher technology and the appropriate volume and weight of the electromagnetic railgun system, so as to be integrated into the ship and withstand the huge electromagnetic pulse generated during launch. The second stage of the research work is to synthesize the launcher and the projectile into a complete system. In the first stage, the US Navy will study a barrel that can be fired multiple times. This barrel can keep the repulsion of the track. The US Navy will also solve the problem of thermal energy management, and increase the initial kinetic energy of the muzzle from the current 8 MJ to 32 MJ, and finally reach 64 MJ. In terms of projectiles, the US Navy needs to study how to improve the launching viability of rail guns (because projectiles may experience 45,000 g gravity acceleration and encounter potential electromagnetic interference effects), and solve problems such as high-speed guided flight and lethality mechanism. Other important research projects include barrel geometry, advanced materials (including synthetic materials), sealing technology and manufacturing technology.
The electromagnetic launcher of the Dalgren Division of the US Naval Surface Warfare Center is the key technical device supporting the "Innovative Naval Prototype" project. According to the instruction of the National Defense Threat Reduction Agency, the device is equipped with a capacitor of 100 MJ (researched by General Atomics) and a refurbished 90 mm barrel on the "green farm electron gun research and development device" developed by Maxwell Technology Company from 1986 to 1999. The electromagnetic transmitter was tested and put into trial operation in June 5438+ 10, 2006, and officially put into use in June 5438+ 10, 2007.
In order to support the "Innovative Naval Prototype" project, the Dahlgren Division of the US Naval Surface Warfare Center will increase the stored electric energy and improve the launcher and terminal area before the end of fiscal year 2008 to assemble a rail gun with an initial kinetic energy of 32 MJ. Under a contract worth $5.4 million, the weapon system department of BAE Systems has designed and renovated a 32 MJ experimental launcher. The launcher is expected to be installed and put into trial operation at the end of June 2007 at the Dalgren branch of the US Navy's surface warfare center. According to BAE Systems, the barrel of this fixed experimental launcher is sealed with laminated steel plates to study the life of the barrel. A committee composed of representatives from American government laboratories, industrial departments and academia provided support for the research activities.
The US Naval Research Office plans to test the 32 MJ railgun at the end of the third quarter of fiscal year 2008. If the research results pass the appraisal, the research will be transferred to the second stage in August 2009, and it is planned to show 100 barrels of 32 MJ launcher and the sealing condition of 32 MJ advanced barrels at the end of fiscal year 20 10.
After evaluating the theoretical design research conducted by BAE Systems, General Forces and Grumman of Northrop from June 65438 to March 2006, the US Naval Research Office selected BAE Systems and General Atomics to conduct technical development and preliminary design research on the 32 Joule railgun for 30 months in June 2006, in order to prepare for the actual deployment of the 64 MJ kinetic energy tactical system. BAE Systems won a contract worth $9.3 million to take charge of the sample gun technology and preliminary design of the rail gun. General Atomics won a contract of $9.6 million, and cooperated with Boeing, L-3 Communication Company, Sparta Composite Materials Company and Jackson Engineering Company to develop the technology needed for the rail gun launcher. In addition, Boeing Company and draper Company jointly study the theory of projectile and integrated launch package, including barrel dynamics of integrated launch package, thermodynamic characteristics of flying projectile and air, lethality and launch survivability, guidance and navigation and control.
As for the advanced pulse force research work, the US Army is responsible for it and plans to show it in FY08. Other research work also includes high energy density capacitors and thermal management of multiple launch activities.
If the "Innovative Naval Prototype" project passes the evaluation in 2009, the work in the 1 phase will be completed in 20 1 1, and the work in the second phase will last until fiscal year 20 15. If all the research work goes smoothly, the Naval Maritime Systems Command can conduct all-round research and development of the railgun in fiscal year 20 15. The tactical system of 64 MJ railgun will be exhibited at sea in fiscal year 20 16, and can be equipped in 2020-26.
On February 28th, 20 12, U.S. military officials announced that U.S. naval engineers successfully test-fired the first prototype railgun made by a military enterprise at the ground combat center in Dalgren, Virginia, which promoted the development of this ultra-long-range new weapon. According to the information released by the navy, the initial velocity of the shell can reach 7000 meters to 8000 meters per second, and it can hit the target 90 kilometers to 180 kilometers away.
Roger Ellis, the project manager of the electromagnetic gun, said that the main purpose of this test is to evaluate the barrel life and overall structure of the prototype gun. He said that this will bring the navy one step closer to the future tactical weapon system. If successfully developed, the electromagnetic gun will greatly enhance the multi-mission capability of the navy. Its muzzle velocity and range far exceed that of ordinary ship-borne artillery, which means that the navy can implement accurate long-range fire support for land military operations, intercept incoming enemy cruise missiles or ballistic missiles and attack enemy ships.
This "prototype" of the rail gun with kinetic energy of 32 MJ, which was manufactured by BAE Ordnance Development Company of the United Kingdom in the United States, has been tested six times in one week, thus starting a two-month evaluation process. In this process, the navy will evaluate the prototype of this electromagnetic gun made by BAE and another prototype made by General Atomic Energy Systems. The prototype gun of the General Atomic Energy System is expected to be completed in April.