Prediction of Drag Aerodynamic Coefficient of the 155mm Projectile Under Axisymmetric Flow Using Different Approaches

Ferfouri, Abdellah; Allouche, Toufik; D. Jerković, Damir; Hristov, Nebojša; Vučković, Milan; Benmeddah, Abdeselem

doi:10.24874/jsscm.2023.17.02.06

Cited by 3 publications

References 13 publications

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Computational Fluid Dynamics Analysis of Drag Reduction in Bullet via Geometric Modifications

Demir,

Çimen,

Yılman

et al. 2024

Bayburt Üniversitesi Fen Bilimleri Dergisi

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In the field of external ballistics, the geometry (shape and structure) of the projectile plays a significant role. This geometry affects a multitude of variables, including air resistance, stability, range, and accuracy. The objective of this study was to decrease the drag coefficients by making different geometric alterations to the Spitzer-type ogive bullet and examining the flow conditions, Mach number, and pressure distributions around the projectile using a three-dimensional numerical simulation. Upon examination of the results, it was observed that the flow exhibited subsonic stagnation zones and a velocity drop upstream of the nose tip. The flow became slightly supersonic as it expanded around the ogive nose and boattail junction. Expansion fans and recompression shocks were detected at the points where the ogive-shaped nose of the projectile transitions to the body, where the boattail-shaped rear of the projectile transitions to the body, and at the base of the projectile. The pressure coefficient value reached its maximum value of CP=0.7 when the air decelerated and dropped to CP=-0.5 as the projectile transitioned from the nose to the body. A gradual decrease in pressure along the projectile surface resulted in a more consistent and lower pressure coefficient compared to the nose. The A3-type bullet, including the most extensive spiral groove, exhibited a 12.4% enhancement in drag reduction as compared to the original bullet. The B-series of straight grooves exhibited a considerable decrease in drag. Nevertheless, the efficacy of helical grooves in regulating flow separation at the tail surpassed that of other methods. The A-series bullets, namely A2 and A3, were well-suited for applications that demanded little aerodynamic resistance. The B-series bullets exhibited enhancements compared to the conventional design and may be deemed suitable for more straightforward production or design limitations.

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Computational Fluid Dynamics Analysis of Drag Reduction in Bullet via Geometric Modifications

Demir,

Çimen,

Yılman

et al. 2024

Bayburt Üniversitesi Fen Bilimleri Dergisi

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Computational analysis of rocket-assisted projectile trajectory

Ferfouri,

Jerković,

Kari

et al. 2024

11th International Scientific Conference on Defensive Technologies - OTEX 2024 - Zbornik Radova

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A computational analysis was carried out in order to study the effect of solid rocket motor operating parameters on the trajectory elements of 155mm rocket-assisted projectile. Two numerical solutions have been programmed for this purpose. The first for the rocket motor internal ballistic calculation. The second is intended for the six degree-of-freedom (6-DOF) trajectory determination for both unpowered and powered flight. The effect of three operating parameters of the solid rocket motor on the trajectory elements was taken into account, namely: (1) thrust-time profile (neutral, regressive or progressive), (2) working time and (3) ignition delay. The results obtained following this analysis are helpful as a preliminary stage in the design of extended range projectiles in order to optimize flight performance.

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Effect of some parameters on the separation process of a saboted bullet

Bui,

Nguyen,

Nguyen

2024

Vojnotehnički glasnik

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Introduction/purpose: In this paper, the influence of muzzle velocity and the initial friction between the sabot and the penetrator of a sub-caliber bullet on the separation process was investigated. A special armor-piercing bullet was chosen as a research object. Methods: A hybrid approach was applied in the study to solve the set tasks. In the first place, the equation system describing the motion of the sabot and the penetrator was established analytically. The aerodynamic drags acting on the sabot and the penetrator were then obtained numerically using CFD methods. Eventually, the equations of motion of the sabot and the penetrator were solved using the Runge-Kutta method to analyze the effect of the bullet muzzle velocity and the initial friction of the sabot and the penetrator on the separation process. Results: The research results have shown the significant influence of the bullet muzzle velocity and the initial friction on the parameters of the sabot and the penetrator at the very moment they completely separate from each other. Based on the obtained data, weapon designers can appropriately select the ballistic and structural parameters for the bullet. Conclusion: The hybrid approach presented in this paper is effective in studying the separation process of armor-piercing saboted bullets. The research results are useful contributions to the field of sub-caliber ammunition. The presented method can be applied in the design process of armor-piercing saboted projectiles of different calibers.

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Prediction of Drag Aerodynamic Coefficient of the 155mm Projectile Under Axisymmetric Flow Using Different Approaches

Cited by 3 publications

References 13 publications

Computational Fluid Dynamics Analysis of Drag Reduction in Bullet via Geometric Modifications

Computational Fluid Dynamics Analysis of Drag Reduction in Bullet via Geometric Modifications

Computational analysis of rocket-assisted projectile trajectory

Effect of some parameters on the separation process of a saboted bullet

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