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

2021 ◽  
pp. 127-138
Author(s):  
K.S. Rogaev ◽  
◽  
A.N. Ishchenko ◽  
V.V. Burkin ◽  
A.S. D’yachkovskiy ◽  
...  
Keyword(s):  
High Energy ◽  
High Density ◽  
Muzzle Velocity ◽  
Internal Ballistics ◽  
Burn Out ◽  
Charge Space ◽  
Propellant Charge ◽  
Individual Particles ◽  
Pyroxylin Powder ◽  
Loading Scheme

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.

Simulated Annealing Algorithm Optimization of the Deterred-Coating Propellant Charge Design

2012 ◽  
Vol 496 ◽  
pp. 99-103
Author(s):  
Zhi Tao Liu ◽  
Dan Dan Ji ◽  
Bin Xu ◽  
Hong Xia Jia ◽  
Xin Liao
Keyword(s):  
Simulated Annealing ◽  
Simulated Annealing Algorithm ◽  
Chamber Pressure ◽  
Mass Ratio ◽  
Algorithm Optimization ◽  
Ballistic Performance ◽  
Muzzle Velocity ◽  
Propellant Charge ◽  
Annealing Algorithm ◽  
Charge Design

In order to get better interior ballistic performance of deterred-coating propellant charge (DCPC), the simulated annealing algorithm optimization of DCPC carries out in this paper. The interior ballistic model of DCPC and its model of simulated annealing algorithm optimization are established based on the characteristics of deterred-coating propellant. Two key parameters of DCPC, the mass ratio of deterred-coating propellants to total propellants and the average perforation pressure of deterred-coating propellant，are optimized for the search of the maximum muzzle velocity under the restricting conditions of maximum chamber pressure and the maximum relative end point of combustion. The optimization results agree well with the standard charge parameters, which justifies the feasibility of the model.

scholarly journals Particle Production in Small and Large Systems at High-Energy and High-Density Frontiers

2021 ◽  
Vol 2021 ◽  
pp. 1-3
Author(s):  
Fu-Hu Liu ◽  
Sakina Fakhraddin ◽  
Raghunath Sahoo ◽  
Edward K. Sarkisyan-Grinbaum ◽  
Bhartendu K. Singh
Keyword(s):  
Particle Production ◽  
High Energy ◽  
High Density ◽  
Large Systems

scholarly journals X-ray studies of the transformation from high- to low-density amorphous water

2019 ◽  
Vol 377 (2146) ◽  
pp. 20180164 ◽  
Author(s):  
Daniel Mariedahl ◽  
Fivos Perakis ◽  
Alexander Späh ◽  
Harshad Pathak ◽  
Kyung Hwan Kim ◽  
...  
Keyword(s):  
Ambient Pressure ◽  
Structural Evolution ◽  
High Energy ◽  
Real Space ◽  
High Density ◽  
Low Density ◽  
X Ray ◽  
Amorphous Ice ◽  
Density State ◽  
Amorphous States

Here we report about the structural evolution during the conversion from high-density amorphous ices at ambient pressure to the low-density state. Using high-energy X-ray diffraction, we have monitored the transformation by following in reciprocal space the structure factor S OO ( Q ) and derived in real space the pair distribution function g OO ( r ). Heating equilibrated high-density amorphous ice (eHDA) at a fast rate (4 K min –1 ), the transition to the low-density form occurs very rapidly, while domains of both high- and low-density coexist. On the other hand, the transition in the case of unannealed HDA (uHDA) and very-high-density amorphous ice is more complex and of continuous nature. The direct comparison of eHDA and uHDA indicates that the molecular structure of uHDA contains a larger amount of tetrahedral motives. The different crystallization behaviour of the derived low-density amorphous states is interpreted as emanating from increased tetrahedral coordination present in uHDA. This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets'.

Synthesis and Characterization of Porous Nano-Crystalline Barium Hexaferrite

2012 ◽  
Vol 622-623 ◽  
pp. 860-863
Author(s):  
S. Hamidizadeh ◽  
A. Ataie ◽  
Amin Nozari
Keyword(s):  
High Density Polyethylene ◽  
Single Phase ◽  
Barium Hexaferrite ◽  
Weight Percent ◽  
High Energy ◽  
High Density ◽  
Synthesis And Characterization ◽  
Polyethylene Composite ◽  
Nano Crystalline

Barium hexaferrite/high density polyethylene composite was prepared from synthesized barium hexaferrite as matrix with 0, 10, 20, 30, 40 wt.% of high density polyethylene via a high energy planetary ball milling for 10 h. The milling products were isostatically pressed and finally sintered at 1250 °C for 1 h. Effect of HDPE content on morphology of the products were investigated using scanning electron microscope (SEM). Vibrating samplemagnetometer (VSM) analysis of single phase BaFe12O19 indicates saturation magnetization and coercivity of 52 emu/g and 4300 Oe, respectively. Visually, as the weight percent of the HDPE increases, more porous structure was observed. Moreover, the density of the sintered sampleslinearly decreased from 4.16 to 1.41 g/cm3 by increasing the amount of HDPE from 0 to 40 wt.%.

scholarly journals Electrical explosion process and amorphous structure of carbon fibers under high-density current pulse igniting intense electron-beam accelerator

2009 ◽  
Vol 27 (3) ◽  
pp. 511-520 ◽  
Author(s):  
Limin Li ◽  
Lie Liu ◽  
Guoxin Cheng ◽  
Lei Chang ◽  
Hong Wan ◽  
...  
Keyword(s):  
Electron Beam ◽  
Current Pulse ◽  
Carbon Fibers ◽  
Electrical Explosion ◽  
High Energy ◽  
High Density ◽  
Density Current ◽  
Explosion Process ◽  
Intense Electron Beam ◽  
Intense Electron

AbstractThe development of pulsed power technology, particularly for inductive energy storage, promotes the extensive discussions of electrical explosion process in high energy density. This paper presents the electrical-explosion behavior of carbon fibers subjected to about 20 kA, ~5 µs high-density current pulse igniting an intense electron beam accelerator. After electrical explosion, and surface rupture, submicron particles, fibrillar and strip-shaped structures were observed, experimentally supporting the microstructure model (skin-core heterogeneity) of carbon fiber. Interestingly, the start and turn-off of the current were followed by radiation pulses with different intensities. It was found that the radiation was focused on the explosion stage which was characterized by an oscillating current. The instabilities of plasma produced during the explosion process play an important role in the microstructure changes of carbon fibers and the radiation generation.

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