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To accelerate the practicality of electromagnetic railguns, it is necessary to use a combination of three-dimensional numerical simulation and experiments to study the mechanism of bore damage. In this paper, a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun, and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network (PFN) is carried out. Various test methods such as spectrometer, fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity, transient magnetic field strength and stress-strain of rail. Combining the simulation results and experimental data, the damage condition of the contact surface is analyzed.

In order to study the spatial-temporal distribution characteristics of electromagnetic rail gun temperature, based on moving grid processing method and mod function method, a 3-D geometric model of electromagnetic rail gun under single launch mode, a 2-D geometric model of electromagnetic rail gun under continuous-fire mode, and the corresponding transient electromagnetic field-temperature field coupling model are established by using the finite element analysis software COMSOL Multiphysics, and the temperature spatial-temporal distribution characteristics in the rail-armature contact area, cross section of rail, and along the rail axis is simulated under single launch and continuous launch. The results show that, under the conditions of single launch and natural cooling, the high temperature area in the rail-armature contact surface is located at the rear of the armature due to the skin effect. The temperature distribution along the axial inner side of rail tends to be higher near the tail and lower near the muzzle, it increases with time, but the peak temperature does not exceed the melting point of copper. Under the continuous launch and natural cooling, after five launches, the peak temperature of the rail increases to 709 °C, which is close to the melting point of copper. Continued launching will cause rapid accumulation of heat in the rail and a rapid increase of peak temperature, resulting in shortened life of the launcher and even launch failure. Therefore, without active cooling measures, the electromagnetic rail gun cannot be used in actual combat. The results of the study are an important guide for the design and thermal management of the cooling system of electromagnetic rail gun. [ABSTRACT FROM AUTHOR]

Aiming at the problem of muzzle arc in the process of electromagnetic railgun launching, a muzzle arc suppression device based on gap arc discharge is designed. The working process and principle of arc suppression device for gap arc striking discharge are analyzed. The key of the design is to ensure that the discharge gap of the arc suppression device can conduct the arc quickly and reliably after the armature is out of the bore. The arc suppression circuit based on the principle of discharge and energy consumption can effectively absorb the residual energy of the muzzle and reduce the arc erosion between the muzzle rail end face and the armature tail. Using Simulink software the simulation model of electromagnetic rail launch system with arc suppression device is built, and the arc suppression current of the arc-starting circuit after the armature exits the muzzle was simulated. Through the simulation calculation of several groups of $R_{s}$ and $L_{s}$ parameters, The influence of the impedance of arc suppression device on the starting time of arc striking, the rising time of arc suppression current, the peak value of arc suppression circuit current, and the current of armature branch is analyzed. The correctness of the simulation model and theoretical analysis calculation is verified by experiments. The waveform analysis of test data shows that the arc striking principle arc suppression device has no effect on the launching performance of the armature when it runs in the bore, and almost all the current flows through the arc suppression circuit after the armature goes out of the muzzle, which can effectively suppress the muzzle arc and improve the launching performance of the rail gun. [ABSTRACT FROM AUTHOR]

In view of the problem that the general electronic instrument and equipment used for transient parameters testing can not work normally under the influence of strong electromagnetic interference, an overload testing device which can effectively shield the strong electromagnetic interference is designed. The shell structure of the testing device is made of multilayer metal materials with good electromagnetic shielding performance, and the internal structure is filled with polyurethane filling technology. The internal circuit system combines low-power design and data acquisition and storage technology to complete the acquisition and recording of overload parameters during the whole flight process. In the actual firing test of electromagnetic railgun, the test device reliably recorded the overload data of the projectile. The result of the experiment shows that the shell structure of the test device has effective electromagnetic shielding for strong electromagnetic fields，and the internal circuit system has successfully acquired the transient overload parameters of the projectile.

U radu je razmatrano trzanje elektromagnetskog šinskog topa i upoređeno sa trzanjem konvencionalnog topa sa barutnim punjenjem. Zaključuje se da je kod elektromagnetskog topa trzanje manje nego kod topa sa barutnim punjenjem. Takođe, pokazano je da pri istim uslovima lansiranja upotreba gasne kočnice topa sa barutnim punjenjem može izmeniti karakteristike trzanja i više ih približiti ponašanju elektromagnetskog topa. / In this paper the electromagnetic rail gun recoil is discussed and compared with the recoil of a conventional, propellant gas driven gun. It is shown that, under similar launch conditions, the recoil of an electromagnetic gun is weaker than that of the powder-driven gun. The use of a muzzle brake on a powder-driven gun can alter its recoil characteristics and make its behavior closer to that of the electromagnetic rail gun.

The dynamic behavior of the rail-gun housing, which includes the rails, is of great importance for the performance of the rail-gun system as a whole. As in the case of conventional guns, the mechanical response of the housing under transient loading (magnetic pressure) can lead to disturbances of the projectile trajectory due to momentum transfer. However, in the case of rail guns, these disturbances can be even more severe as the armature performance can be very sensitive to variations of the normal forces at the contact interface. In previous developments, the structural mechanics of a rail gun with discrete supports were analyzed using the conventional boundary conditions. In this paper, further considerations are focused on describing a specific distributed energy storage (DES) operation technique which was developed at ISL. Using the finite-element technique, numerical calculations were performed for the ISL rail-gun EMA3 equipped with a one-stage DES. Its caliber was 15 mm \times 30 mm and produced a typical muzzle velocity of up to 1600 m/s, as well as peak currents of about 600 kA. Three spatially different DES configurations were used. The obtained results were then compared to the conventional breech-fed configuration. [ABSTRACT FROM AUTHOR]