Muzzle Voltage Characteristics of Railguns

Muzzle voltage is an essential diagnostic tool used in both contact resistance modeling and transition determination. However, it is challenging to stem the necessary meanings from the collected measurements. In this study, EMFY-3 launch experiments are used to model muzzle voltage characteristics to understand the transition mechanism better. These experiments have muzzle energies in the range between 1.69-2.85 MJ in ASELSAN Electromagnetic Launcher Laboratory. Six different launch tests with various rail current waveforms that ranged between 1.5-2.1 MA are used to investigate different scenarios. Some parameters which affect muzzle voltage are calculated with the 3-D Finite Element Method (FEM), i.e., rail mutual inductance $\mathrm{L_m}$. Muzzle voltages are decomposed into subsections; each subsection is calculated with proper models. Simulation results are coherent with experimental measurements. Findings are compared with previous studies, and differences are explained with possible reasons. Even though we could not conclusively resolve which physical quantity starts to transition, the study showed that transition does not form a specific muzzle velocity, armature action integral, or down-slope rail current ratio.

Muzzle Voltage Characteristics of Railguns

Muzzle voltage is an essential diagnostic tool used in both contact resistance modeling and transition determination. However, it is challenging to stem the necessary meanings from the collected measurements. In this study, EMFY-3 launch experiments are used to model muzzle voltage characteristics to understand the transition mechanism better. These experiments have muzzle energies in the range between 1.69-2.85 MJ in ASELSAN Electromagnetic Launcher Laboratory. Six different launch tests with various rail current waveforms that ranged between 1.5-2.1 MA are used to investigate different scenarios. Some parameters which affect muzzle voltage are calculated with the 3-D Finite Element Method (FEM), i.e., rail mutual inductance $\mathrm{L_m}$. Muzzle voltages are decomposed into subsections; each subsection is calculated with proper models. Simulation results are coherent with experimental measurements. Findings are compared with previous studies, and differences are explained with possible reasons. Even though we could not conclusively resolve which physical quantity starts to transition, the study showed that transition does not form a specific muzzle velocity, armature action integral, or down-slope rail current ratio.

CONCEPTION OF “SILENT” MORTAR PROJECTILE. PART I – REVIEW OF EXISTING DESIGNS

Theoretical introduction into operational principles and designs of typical “silent” mortars and their ammunition is presented in the paper. The principle of operation and structure of “silent” mortar projectile are presented. In the following chapters a review of selected designs of “silent” mortar projec-tiles is included. After analysing the data the final calibre of the projectile and other key parameters to be deployed in own project were accepted. Following designing parameters were accepted in the summary: calibre 60 mm, mass of the projectile 1.8 kg, minimum muzzle velocity 125 m/s.

Analysis of Probability Distribution of Muzzle Velocity for Chrome Plated Barrel

To confirm the change of muzzle velocity and the most suitable probability distribution model of the 155 mm K9 howitzer barrel with chrome plating and changed rifling. Using a statistical program, the muzzle velocity were plotted on a normal distribution, a 2-parameter and 3-parameter Weibull distribution on a probability paper. Also, statistical parameters were estimated and muzzle velocity fitness test and probability of K676 charge were plotted. In both the chrome-plated with standard rifling and changed rifling for K9 barrel, the 2-parameter and 3-parameter Weibull distribution were skewed to the left compared to the normal distribution. It was confirmed that the muzzle velocity of the K9 barrel with chromium-plated is suitable for the normal distribution and 3-parameter Weibull distribution model.

SUGGESTIONS FOR TYPICAL METHODS OF USING DOPPLER RADAR SYSTEMS OF TRAJECTORY MEASUREMENTS DURING TESTS OF ARTYLLERY ARMAMENT AND ITS AMMUNITION

The article analyzes the report documentation of the tests in which the Doppler radar trajectory measurement system MFTR–2100/40 and the muzzle velocity measurement system SL-520PE were used to determine the trajectory parameters of artillery armament. The purpose of the article is to provide proposals for standard methods of using Doppler radar systems of trajectory measurements when testing artillery armament and its ammunition. The proposals for these standard methods are based on the experience of using the MFTR–2100/40 radar system and the SL–520PE muzzle velocity measurement system during the tests of the latest specimens of artillery and ammunition and relate to typical Doppler radar systems. When choosing the position and mode of operation of such Doppler radar trajectory measurement systems, it is always necessary to take into account safety measures, instructions for their operation, technical features (capabilities) of radar systems specified in this article, considering the interference environment during firing (shot) of artillery armament and experiment (test) conditions. Placing typical Doppler radar systems when taking measurements in unplanned places is dangerous for the crew and measuring instruments and leads to partial or complete loss of measuring trajectory information and reduced measurement accuracy. Abovementioned proposals are offered to be taken into account when developing methods of trajectory measurements using typical Doppler radar systems during testing artillery armament and its ammunition. Methods of measurements using standard Doppler radar systems of trajectory measurements should be developed in accordance with current standards (GOST 8.010-99, GOST V 15.211-78 and others) for a particular test, taking into account the results of analysis of the characteristics of samples to be evaluated, measuring instruments used, conditions and locations of measurements.

A STUDY OF THE COMBUSTION OF HIGH-DENSITY PROPELLANTS IN A MODEL BALLISTIC INSTALLATION

In internal ballistics of barrel systems, a promising trend is related to the increasing of projectile muzzle velocity by means of high-energy propellants utilized as a traveling charge. The use of a loading scheme with a traveling charge allows one to increase the loading density and to redistribute the energy of powder gases in the space behind the projectile, which leads to a significant increase in the muzzle velocity of the projectile. To attain the listed advantages, it is necessary to know the laws of dispersion and combustion of the propellants used as traveling charges, providing non-digressive gas entry into the charge space. In this work, a comprehensive experimental and theoretical study of the laws of dispersion and combustion of high-density propellants under dynamic pressures, provided in a model ballistic installation, is carried out. The main ballistic characteristics of shots are obtained, which use a classic scheme of loading with a propellant charge made of pyroxylin powder and a scheme with a traveling charge, where, in addition to the propellant charge, a high-density propellant is included. All the experiments are simulated in a software package, taking into account the presence of the high-density propellants in the propellant charge, dispersing into individual particles that burn out while moving along the barrel. As a result of comparing the calculated and experimental data, plausible patterns of the distribution of gas-dynamic parameters are obtained using the classic loading scheme and the loading scheme with a travelling high-density propellant charge.

Analysis of thermal and gas-dynamic characteristics of different types of propellant in small weapons

This paper presents a numerical and an analytical approach for calculation of internal ballistics parameters through determination of thermal and gas- dynamic characteristics. The calculated parameters are validated through experimental tests on a real weapon system. The internal ballistic calculations are provided for two types of propellants using an analytical and a numerical model. Calculations and tests are performed for an anti-material rifle 12.7 mm. Weapon and ammunition testing is carried out according to the C.I.P. (Permanent International Commission) standard. Theoretical and experimental results for the gunpowder gases pressure and the muzzle velocity are compared. The good agreements between the calculated and the measured pressures and velocities increase the reliability of the estimated gunpowder gas temperatures in the barrel. The obtained results enable analysis and comparison of the output internal ballistics parameters for different types of propellant applications.