Defense and Security Studies <p>The journal roughly covers all areas of science and technology related to the defense, military applications, and security in all five domains including air, land, sea, space, and cyberspace. The goal of this journal is to provide a knowledge-sharing platform without any restriction to researchers, developers, industrial practitioners, educators over the Globe. Gold open access is encouraging especially for young researchers to link local knowledge to the global audience. Defense industry practitioners, academic researchers, and student schools will have benefit from wider access to the research without any restriction. </p> Research and Development Academy en-US Defense and Security Studies <p style="text-align: justify; line-height: 14.4pt; background: white; margin: 11.5pt 0in 11.5pt 0in;"><span style="font-size: 11.0pt;">Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a </span><a href=""><span style="font-size: 11.0pt; color: #007ab2;">Creative Commons Attribution License</span></a><span style="font-size: 11.0pt;"> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</span></p> <p style="text-align: justify; line-height: 14.4pt; background: white; margin: 11.5pt 0in 11.5pt 0in;"><span style="font-size: 11.0pt;">This journal <strong>permits</strong> and <strong>encourages</strong> authors to post items/PDFs submitted to the journal on personal websites or institutional repositories after publication, while providing bibliographic details that credit its publication in this journal.</span></p> An overview of Gurney method for estimating the initial velocities of fragments for high explosive munition <table width="794"> <tbody> <tr> <td width="622"> <p>The literature survey, related to the initial velocity of fragments for HE ammunition is presented. The basic Gurney model for fragment initial velocity, that can be used for different munition configuration, is presented. The research we performed using the Gurney method for a different projectile types is given.</p> </td> </tr> </tbody> </table> Alan Catovic Copyright (c) 2020 Alan Catovic 2020-12-23 2020-12-23 1 10.37868/dss.v1.id72 Axial Force Coefficient of APFSDS Projectile <table width="635"> <tbody> <tr> <td width="498"> <p>Armor-piercing ammunition is primarily used to combat against heavy armored targets (tanks), but targets can be light armored vehicles, aircraft, warehouse, structures, etc. It has been shown that the most effective type of anti-tank ammunition in the world is the APFSDS ammunition (Armor Piercing Fin Stabilized Discarding Sabot). The APFSDS projectile flies to the target and with his kinetic energy acts on the target, that is, penetrates through armor and disables the tank and his crew. Since the projectile destroys target with his kinetic energy, then it is necessary for the projectile to have the high impact velocity.</p> <p>The decrease in the velocity of a projectile, during flight, is mainly influenced by aerodynamic forces. The most dominant is the axial force due to the laid trajectory of the projectile. By knowing the axial force (axial force coefficient), it is possible to predict the impact velocity of the projectile, by external ballistic calculation, in function of the distance of the target, and to define the maximum effective range from the aspect of terminal ballistics.</p> <p>In this paper two models will be presented for predicting axial force (the axial force coefficient) of an APFSDS projectile after discarding sabot. The first model is defined in STANAG 4655 Ed.1. This model is used to predict the axial force coefficient for all types of conventional projectiles. The second model for predicting the axial force coefficient of an APFSDS projectile, which is presented in the paper, is the CFD-model (Computed Fluid Dynamics).</p> </td> </tr> </tbody> </table> Ammar Trakic Copyright (c) 2020 Ammar Trakic 2021-01-07 2021-01-07 1 10.37868/dss.v1.id63