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Journal articles on the topic 'Projectiles'
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1
Harris, A. L. "Projectile Coherence Effects in Twisted Electron Ionization of Helium." Atoms 11, no. 5 (May 3, 2023): 79. http://dx.doi.org/10.3390/atoms11050079.
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Over the last decade, it has become clear that for heavy ion projectiles, the projectile’s transverse coherence length must be considered in theoretical models. While traditional scattering theory often assumes that the projectile has an infinite coherence length, many studies have demonstrated that the effect of projectile coherence cannot be ignored, even when the projectile-target interaction is within the perturbative regime. This has led to a surge in studies that examine the effects of the projectile’s coherence length. Heavy-ion collisions are particularly well-suited to this because the projectile’s momentum can be large, leading to a small deBroglie wavelength. In contrast, electron projectiles that have larger deBroglie wavelengths and coherence effects can usually be safely ignored. However, the recent demonstration of sculpted electron wave packets opens the door to studying projectile coherence effects in electron-impact collisions. We report here theoretical triple differential cross-sections (TDCSs) for the electron-impact ionization of helium using Bessel and Laguerre-Gauss projectiles. We show that the projectile’s transverse coherence length affects the shape and magnitude of the TDCSs and that the atomic target’s position within the projectile beam plays a significant role in the probability of ionization. We also demonstrate that projectiles with large coherence lengths result in cross-sections that more closely resemble their fully coherent counterparts.
2
Kim, Jonghoek. "Autonomous Balloon Controls for Protection against Projectiles with Known Destinations." Applied Sciences 11, no. 9 (April 29, 2021): 4077. http://dx.doi.org/10.3390/app11094077.
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This article tackles autonomous balloon controls for protection against projectiles with known destinations. We introduce a defense strategy against an enemy projectile trying to reach a destination, such as a military base, which is known a priori. We further assume that the position of the platform that launches the projectile is known in advance. Because both the platform and the projectile’s destination are known in advance, we can predict the trajectory of the projectile before the projectile is launched. The proposed defense strategy is to deploy multiple balloons on the projectile’s feasible paths so that they block the incoming projectile effectively. Each balloon has GPS sensors for locating itself and IR sensors to detect an incoming projectile. Once the projectile is sufficiently close to a balloon, the balloon explodes to destroy the projectile. Since the projectile’s purpose is reaching its destination, the balloons can effectively intercept the projectile using this blocking strategy. As far as we know, this article is novel in utilizing multiple balloons for protection against an enemy projectile. The effectiveness of our defense strategy is further verified utilizing MATLAB simulations.
3
Luo, Qiao, and Xiaobing Zhang. "Numerical simulation of serial launch process of multiple projectiles considering the aftereffect period." International Journal of Numerical Methods for Heat & Fluid Flow 27, no. 8 (August 7, 2017): 1720–34. http://dx.doi.org/10.1108/hff-04-2016-0151.
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Purpose The numerical simulation of the serial launch process of multiple projectiles is an important engineering problem. However, the projectiles’ motion law is hard to obtain completely only by interior ballistic model. The muzzle flow field affects the projectiles’ velocities when the projectiles pass through it. Also, the propellant gas from previous projectiles may decelerate the later projectiles. Therefore, the aftereffect period should be simulated together with the interior ballistic process of multiple projectiles when researching the serial launch process for accurate motion law of the projectiles. Design/methodology/approach The computational fluid dynamics (CFD) software is used to simulate the muzzle flow field. A one-dimensional two-phase reaction flow model is implemented in a computational code for the numerical simulation of gas-solid two-phase reaction flow, during the serial launch process. The computational code is coupled with CFD software by a user-defined function. Findings Compared with the first projectile, the formation process of the shock bottle of the second projectile is different. After the projectile head flies out of the muzzle, the projectile head pressure decreases rapidly, but then, it is not always equal to 0.1 MPa. After the projectiles leave the muzzle, the velocity increments of each projectile are mainly determined by muzzle pressure. Originality/value This paper presents a prediction tool to understand the projectiles’ motion law during the serial launch process of the multiple projectiles considering aftereffect period, and can be used as a research tool for future ballistic studies of a serial launch system of multiple projectiles.
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MERDA, Tomasz MERDA. "SEMI STABLE FLIGHT OF SUPERSONIC MORTAR PROJECTILE." PROBLEMY TECHNIKI UZBROJENIA 149, no. 1 (August 28, 2019): 23–46. http://dx.doi.org/10.5604/01.3001.0013.3769.
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Significantly large dispersion of projectiles was observed at firing a specific type of a supersonic mortar projectile being devel-oped in the frame of RAK ANUNICJA program. The flying paths, parameters and reasons of falling points dispersion were determined for tested projectiles with a model of external ballistics describing the projectile as a rigid body. Analysis of received results has indicated that the dispersion was not caused by an aerodynamic jump but by an effect which has not been described yet in the literature and is named here as “projectile’s semi-stable flight”. The paper includes a description of the effect with reasons and parameters affecting its occurrence, and a method for determination of the equilibrium nutation angle which plays a key role in this effect.
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Xing, Bingnan, Chengxin Du, Zhonghua Du, and Wenxin Yang. "Robust Optimization Design of the Aerodynamic Shape and External Ballistics of a Pulse Trajectory Correction Projectile." Applied Sciences 13, no. 12 (June 10, 2023): 7007. http://dx.doi.org/10.3390/app13127007.
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To improve the tactical and technical performance of pulse correction projectiles while maintaining stability in uncertain conditions and considering practical engineering constraints, this study performs a multi-objective robust optimization design of the aerodynamic shape and external ballistics of a projectile. The study utilizes an aerodynamic force engineering algorithm and numerical trajectory calculations to obtain the projectile’s performance responses within the Latin hypercube design space. To enhance optimization efficiency, a stochastic Kriging surrogate model is established to capture the inherent uncertainty of limited input data. Ultimately, a Pareto optimal solution for the projectile is obtained using a non-dominated sorting multi-objective sparrow search algorithm. The results of this study demonstrate that the consideration of design uncertainty in the robust optimization of pulse correction projectiles leads to significant enhancements in both lateral correction ability and range while satisfying flight stability requirements. Moreover, when compared to deterministic optimization, the performance variability of the design is markedly improved. This research methodology provides valuable insights for optimizing the performance of pulse correction projectiles.
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Meda, T., and A. Rogala. "Experimental Validation of the Mean Pitch Theory." Journal of Physics: Conference Series 2090, no. 1 (November 1, 2021): 012042. http://dx.doi.org/10.1088/1742-6596/2090/1/012042.
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Abstract There are several types of exterior ballistic models used to calculate projectile’s flight trajectories. The most complex 6 degree of freedom rigid body model has many disadvantages to using it to create firing tables or rapid calculations in fire control systems. Some of ballistic phenomena can be simplified by empirical equations without significant loss of accuracy. This approach allowed to create standard NATO ballistic model for spin stabilized projectiles named Modified Point of Mass Model (PM Model). For fin (aerodynamically) stabilized projectiles like mortar projectiles simple Point of Mass Model is commonly used. The PM Model excludes many flight phenomena in calculations. In this paper authors show the mean pitch theory as an approximation of the natural fin stabilised projectile pitch during flight. The theory allows for simple improvement of accuracy of the trajectories calculation. In order to validate the theory data obtained from shooting of supersonic mortar projectiles were used. The comparison of accuracy between simple PM Model and PM Model including mean pitch theory were shown. Results were also compared with the angle of response theory.
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Zhang, Lite, Chengwei Zhang, Huixia Jia, and Ruoling Dong. "Effects of Lateral Flows on the Supercavitation and Hydrodynamic Characteristics of Underwater Series and Parallel High-Speed Projectiles." Journal of Marine Science and Engineering 11, no. 4 (April 21, 2023): 878. http://dx.doi.org/10.3390/jmse11040878.
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In this paper, the supercavitation of the parallel and tandem projectiles moving underwater with high-speed under the condition with/without lateral flows is numerically simulated by the volume of fraction (VOF) model. The motion of the projectiles was handled by the overlapping grid and six degrees of freedom (DOF) techniques. The supercavitation evolution and the hydrodynamic characteristics of the projectiles were analyzed for the parallel and tandem projectiles under different conditions. The results show that the cavity shape is symmetrical under the condition without lateral flows, but is no longer symmetrical under the conditions with lateral flows. The asymmetry of the cavity contour increases with the velocity of the lateral flow. For the parallel projectiles, the change trends of the axial velocity of projectile 1 and projectile 2 are nearly the same. The offset velocity of projectile 1 and projectile 2 increases with the increase in the velocity of the lateral flow. The deflection angle of projectile 1 decreases with the increase in the lateral flow velocity but that of projectile 2 increases with the increase in the lateral flow velocity. At t = 3.0 ms, the deflection angle of projectile 2 is up to 20° under the condition of the lateral flow velocity of 11.25%, while the deflection angle of projectile 1 and 2 under other conditions is in the range of 5°. For the tandem projectiles, the axial velocity of projectile 1 gradually decreases. The change trend of the axial velocity of projectile 2 at first is the same as that of projectile 1, and then the change is dependent on the velocity of the lateral flow. Under the condition of the lateral flow velocity with 11.25%Vp, projectile 2 cannot enter the cavity of the front projectile. The change trend of the axial velocity of projectile 2 is similar as but somewhat slower than that of projectile 1. For the parallel projectiles, the ballistic stability of the projectile on the oncoming side is better than that of the projectile on the backflow side. Whether parallel or tandem projectiles, the ballistic stability of projectile 2 becomes worse with the increase in the lateral flow velocity.
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Catovic, Alan. "Comparison of Penetration Capability of Several Contemporary 5.56×45 mm Projectiles into Hard Targets." Advances in Military Technology 19, no. 1 (August 4, 2024): 71–90. http://dx.doi.org/10.3849/aimt.01870.
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The analysis was performed on six commonly used 5.56 × 45 mm projectile types (M193, M855, M855A1, L31A1, M995, and AP45). The projectile’s impact velocity (chosen as 900 m/s) was the same in the examination process. This made it possible to assess how the projectile’s design has affected its performance against a hard steel target. These evaluations included numerical simulations (Ansys Autodyn) of projectile impacts. Using the available experimental data, the materials in the computational model were first validated. A short description and CAD model of projectiles is also given. Relevant conclusions were reported.
9
Xiao, Yihua, Huanghuang Dong, Haifei Zhan, and Aihua Zhu. "Numerical study on the perforation of steel plates by multiple projectiles." Engineering Computations 35, no. 7 (October 1, 2018): 2629–51. http://dx.doi.org/10.1108/ec-03-2018-0107.
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Purpose Metal plates are usually used as protective shields of engineering structures, which probably undergo multiple projectile impacts resulting from gunshot and blast. Though a large number of studies have been conducted on the performance of metal plates under a single projectile impact, few studies have explored their performance under multiple projectile impacts. This paper aims to explore the performance of Weldox 460 E steel plates against multiple projectile impacts through numerical simulation. Design/methodology/approach A three-dimensional coupled finite element (FE) and smoothed particle hydrodynamics (SPH) model was developed to simulate the perforation of a 12-mm-thick Weldox 460 E steel plate by an ogival projectile. The model was verified by existing experimental data. Then, it was extended to investigate the same target plate subjected to impacts with multiple projectiles. Simultaneous impacts with different number of projectiles, as well as sequential impacts with two projectiles, were considered. Findings Effects of spacing between projectiles on residual velocity of projectile, ballistic limit and failure mode of target were revealed for simultaneous impacts. Effects of spacing and axial distance between projectiles on residual velocity of projectile were explored for sequential impacts. Originality/value This work developed an advanced FE–SPH model to simulate perforation of steel plates by multiple projectiles, and revealed the effects of multiple impacts on ballistic performance of steel plates. It provides guidance for the design of protective structures/shields in various engineering applications.
10
Wei, Ping, Shoufa Wang, Wenrong Yan, and Xin Yu. "Analysis and Calculation of the Best Center of Mass for Supercavitating Projectile." Journal of Sensors 2022 (February 23, 2022): 1–10. http://dx.doi.org/10.1155/2022/9521236.
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Currently, the supercavitating projectiles mostly rely on experience or experimental results to test the shape of the projectile; however, the cost of the experiment is relatively high, and there is no specific criterion to judge whether the underwater projectile is stable. To solve the aforementioned problems, we study the motion stability and establish motion equations for supercavitating projectiles. Through theoretical analysis and simulation calculations, the optimal center of mass position is designed to optimize the motion performance of underwater supercavitating projectiles. We think this work can provide theoretical support for the optimal design of underwater supercavitating projectiles.
11
Shen, Zhengxiang, Hu Chen, Du Wang, Shuqiang Yuan, Dingyue Cheng, and Guorong Zhu. "Failure Behaviours of Steel Projectiles with Localised Melting Against Armour Plates." Defence Science Journal 69, no. 5 (September 17, 2019): 489–94. http://dx.doi.org/10.14429/dsj.69.13338.
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The surface remelting technology of high energy beam can locally weaken the case for controlled fragmentation, which may affect the survivability of the impacting projectiles. Failure behaviours of steel projectiles with melted layers grid normally perforating armour plates was investigated. The results reveal that shear fracture mainly occurs in the nose region of projectiles due to high loading, and the melting zone of projectiles can keep integrity with no damage, which means the survivability of projectile can be assured. Furthermore, an analytical model was proposed to the structural analysis of projectile, which is in accordance with the test results.
12
Hvistendahl, M. "Of Population Projections and Projectiles." Science 329, no. 5998 (September 16, 2010): 1460. http://dx.doi.org/10.1126/science.329.5998.1460.
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Salimipour, Seyed Erfan, Ali Reza Teymourtash, and Mojtaba Mamourian. "Investigation and comparison of performance of some air gun projectiles with nose shape modifications." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 233, no. 1 (March 4, 2018): 3–15. http://dx.doi.org/10.1177/1754337118759159.
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Shooting accuracy of air gun projectiles is very important in sport tournaments and has always been questioned by enthusiasts. For this purpose, the performance of four samples of air gun projectiles (pellets) with various shapes and calibers of 4.5, 5.5 and 6.35 mm was studied in this article. The projectiles were four basic shapes: flat nose, sharp nose, round nose and spherical. After these projectiles were modeled geometrically, the three-dimensional compressible turbulent Navier–Stokes equations and dynamic equations of the projectiles’ motion were solved in a coupled form and in a moving computational grid. The computed results describe the trajectory, velocity variations and the altitude loss of the projectiles with time and location. Comparisons indicate that the round nose projectile had the best performance at long distances compared to the other samples. The flat nose projectile exhibited great performance at short distances, but behaved weakly at long distances. In addition, the effect of nose shape on the performance of the sharp and round nose projectiles was studied and the optimum nose shapes were identified.
14
Ding, Liangliang, Jingyuan Zhou, Xianwen Ran, Wenhui Tang, Xiaoguang Xue, and Yuli Zhao. "Theoretical Model of Radial Scattering Velocity of Fragments of the Reactive Core PELE Projectile." Symmetry 12, no. 7 (July 17, 2020): 1190. http://dx.doi.org/10.3390/sym12071190.
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PELE projectile is a new type of armor-piercing warhead and has a more obvious fragmentation effect, which solves the problem of insufficient after-effects of conventional armor-piercing projectiles. Reactive material is a new type of energetic material, which has some characteristics similar to the traditional explosives but has better mechanical properties. Reactive material is insensitive under normal conditions, and it can release huge energy under external impact loading. This paper hopes to study the application of reactive materials to the inner core of PELE projectiles to further improve the fragmentation effect of PELE projectiles. The fragmentation effect of PELE projectile is mainly reflected in the radial scattering velocity of fragments after it perforates the target plate. In this paper, three energy sources for the radial scattering of fragments were obtained by analyzing the penetration process of PELE projectile, that is, the axial kinetic energy of outer casing, the radial compression potential energy generated by the inner core to the outer casing, and the chemical energy released by the reactive core material. Based on the simplification and assumptions, the theoretical model of radial scattering velocity of fragments of the reactive core PELE projectile was established. In addition, numerical simulations were carried out to verify the theoretical model. The results show that the numerical simulation results are in good agreement with the theoretical calculation results, which indicates that the model established in this paper is scientific and reasonable. The reactive core PELE projectile has a more significant fragmentation effect, which further enhances the comprehensive damage power of traditional PELE projectile. The theoretical model established in this paper can quickly assess the power of reactive core PELE projectile’s fragmentation effect, which can be used to provide guidance and reference for engineering application.
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Martinez-del-Campo, Eduardo, Leonardo Rangel-Castilla, Hector Soriano-Baron, and Nicholas Theodore. "Magnetic resonance imaging in lumbar gunshot wounds: an absolute contraindication?" Neurosurgical Focus 37, no. 1 (July 2014): E13. http://dx.doi.org/10.3171/2014.7.focus1496.
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Object Performance of MR imaging in patients with gunshot wounds at or near the lumbar spinal canal is controversial. The authors reviewed the literature on the use of MR imaging in gunshot wounds to the spine. They discuss the results from in vitro and clinical studies, analyze the physical properties of common projectiles, and evaluate the safety and indications for MR imaging when metallic fragments are located near the spinal canal. Methods A review of the English-language literature was performed. Data from 25 articles were analyzed, including 5 in vitro studies of the interaction between 95 projectiles and the MR system's magnetic fields, and the clinical outcomes in 22 patients with metallic fragments at or near the spinal canal who underwent MR imaging. Results Properties of 95 civilian and military projectiles were analyzed at a magnet strength of 1, 1.5, 3, and 7 T. The most common projectiles were bullets with a core of lead, either with a copper jacket or unjacketed (73 [76.8%] of 95). Steel-containing (core or jacket) projectiles comprised 14.7%. No field interaction was evident in 78 (96.3%) of the 81 nonsteel projectiles. All steel projectiles showed at least positive deflection forces, longitudinal migration, or rotation. Heating of the projectiles was clinically insignificant. Image artifact was significant in all 9 steel bullets tested, but was not significant in 39 (88.6%) of the 44 nonsteel bullets tested. Overall, 22 patients with complete (82%) and incomplete (14%) spinal cord injury secondary to a projectile lodged inside the spinal canal underwent MR imaging. Discomfort and further physical or neurological deficits were not reported by any patient. Two patients with spinal cord injuries underwent MR imaging studies before surgical decompression and had subsequent, significant neurological improvement. Conclusions Metallic implants near or at the spinal canal are a relative contraindication for MR imaging. However, safe MR imaging might be feasible when a projectile's properties and a patient's individualized clinical presentation are considered.
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Головань, В., С. Нікул, О. Кравчук, Д. Максимчук, and Ю. Сініло. "ПЕРСПЕКТИВИ РОЗВИТКУ СНАРЯДІВ КАЛІБРУ 155 ММ." Collection of scientific works of Odesa Military Academy, no. 20 (December 14, 2023): 87–92. http://dx.doi.org/10.37129/2313-7509.2023.20.87-92.
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This research paper is devoted to the prospects of development of 155 mm caliber projectiles. The projectiles of this caliber are important elements of artillery armament used in many countries, particularly in NATO countries. The paper reviews the current state of the art of 155 mm projectiles, technological innovations to improve these projectiles, challenges and limitations, development prospects and conclusion. A general overview of 155 mm caliber projectiles, their main characteristics and uses is provided. Technological innovations used to improve the projectiles, in particular new materials and control systems, are proposed. The challenges and limitations faced by 155 mm caliber projectiles are discussed in detail. This includes discussion of projectile size and weight, firing accuracy, cost and availability, air defense, and ethical aspects of weapon use. Prospects for the development of 155 mm caliber projectiles are presented. New technologies and innovations that can improve their effectiveness, maneuverability, and ability to counter the enemy are discussed. In particular, the use of automated control systems, improved guidance and navigation systems, and the use of new materials are explored. A conclusion is provided that summarizes the results of the study and draws conclusions regarding the future development of 155 mm caliber projectiles. It is noted that an integrated approach and innovative solutions are needed to overcome the challenges and limitations and to ensure the availability and effectiveness of these projectiles in the modern combat environment. This paper aims to contribute to the understanding of the future prospects of 155 mm caliber projectiles and to provide a basis for further research and development in this area. Keywords: 155 mm projectiles, artillery ammunition, ballistics, precision guidance systems, projectile design, smart ammunition, artillery technology, lethality enhancement, drive systems, future trends.
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SULAKSONO, A. "COLD FUSION REACTIONS USING NEUTRON-RICH PROJECTILES." International Journal of Modern Physics E 22, no. 08 (August 2013): 1350061. http://dx.doi.org/10.1142/s0218301313500614.
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This paper studies the formation cross-sections of super heavy (SH) nuclei in some cold fusion reactions of radioactive neutron-rich projectiles with double-magic 208 Pb target. In this study, the cross-sections of capture, fusion and evaporation residues in one- and two-neutron (1n and 2n) channels are calculated by using neutron-rich Fe , Ni and Zn projectiles are compared to the cross-sections calculated using stable Fe , Ni and Zn projectiles. The heights of fusion barrier and their positions in all reactions considered in this study are also compared to the heights and positions calculated using the estimation method proposed by Dutt and Puri. For cold fusion reactions with stable Fe , Ni and Zn projectiles, the heights of fusion barrier and the cross-sections of evaporation residues in 1n and 2n channels are compared to their corresponding experimental data. In general, for reactions using projectiles with the same proton number, the neutron-rich projectile is found to yield relatively-heavier mass of SH nucleus and larger evaporation residue cross-section, compared to those of the corresponding stable projectiles. However, in certain reactions, the cross-sections of neutron-rich projectile can be slightly larger or slightly smaller than that of the corresponding stable projectile. This behavior is highly affected by the charge of projectile and the fission barrier of the formed compound nucleus (CN). In addition, the 292114 is found to be the heaviest compound nucleus formed in cold fusion reaction by using neutron-rich nuclei as the projectile, but the cross-section of evaporation residue in one-neutron channel is still around few pico barns (pb).
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Boriak, Kostiantyn. "The Improvements of Ballistic Characteristics of Artillery Projectiles of 152 and 155 mm Calibers." Bulletin of the Military University of Technology 72, no. 2 (June 30, 2023): 83–96. http://dx.doi.org/10.5604/01.3001.0054.3657.
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The existing methods of manufacturing artillery projectiles with calibration and markingonly in one parameter for measuring the total mass by statically weighing do not take into accountthe dynamics when a projectile moves in the air, namely, the dynamic unbalance of the mass owing tounevenly distributing the mass throughout the geometric shape of the projectile. When flying alonga ballistic trajectory, projectiles rotate in the air with a high angular velocity in the range of 200–500rev/min and, therefore, they are similar in the dynamics of the rotating motion to the rotation of rigidrotors. Based on the presence of manufacturing tolerances in the metalworking of the body, artilleryprojectiles can have dynamic unbalance and a large amount of unbalance, which can exceed theallowable norm for rigid rotors by 15–20 times and unpredictably affect the dynamics of a projectilewhen moving along a ballistic trajectory. The solution to this problem is seen in the improvement ofthe methods being used for manufacturing artillery projectiles by performing an additional manufacturingoperation for correcting (diminishing) the unbalance vector, which will reduce the lateraldeviation and drift of the projectiles in flight as well as stabilize their dynamic parameters whenmoving along a ballistic trajectory in the air, and that will certainly lead to an increase in the rangeof the projectiles and enhancement of the accuracy of hitting the target. The article proposes severaloptions for the practical implementation of the manufacturing operation for correcting the unbalancevector of projectiles in one plane. When applying the method of balancing the projectiles by addingmissing metal (mass), it is proposed to place the corrective weight in a special “corrective groove” onthe outer surface of the projectile body, which can be preliminarily made on a metalworking machineduring the general processing of the projectile body. To ensure the strength of fixing in the grooves ofthe corrective weights from the influence of the pressure of powder gases on them when firing froma gun, it is proposed to make the geometrical profile of the groove in the cross section of a trapezoidalshape of the dovetail type. When applying the method of removing excess metal (mass), it is proposedto make holes on the outer surface of the projectile body by milling (or drilling). The mass and place (angle) of the correction, the geometric dimensions, and the number of corrective weights or correctiveholes shall be preliminarily determined in the course of balancing the projectiles on a balancingstand. It is proposed to introduce the marking of projectiles in five classes through two parametersof mass and their deviations from the norm: the first of which is the measurement of the total massof the projectile in statics, and the second one is the measurement of unbalance of the mass of theprojectile in the form of the amount of unbalance in dynamics.Keywords: projectiles, ballistic characteristics, balancing, calibrating, unbalance vector
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Xing, Jie, and Yin Xian Duo. "Vibration Influence of Artillery Autoloader Analysis and Testing." Advanced Materials Research 711 (June 2013): 540–44. http://dx.doi.org/10.4028/www.scientific.net/amr.711.540.
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The inconsistency of the projectile's seizing-bore stroke of the large caliber gun during feeding process will lead to differences of the volume of propellant chamber and starting pressure of projectiles.It will also affect guns' muzzle velocity and firing accuracy.In order to improve the positioning accuracy of projectiles in an arm-type autoloader,first of all,high speed photography was used and only to find that there will be vibrations of projectiles in the direction of gravity.The vibrations will consume kinetic energy of the projectile and contribute to inconsistency of the retaining force.By means of analyzing the working mechanism of the rammer,the motion relationship among the parts during ramming process came to clear eventually.Then the position of the exciting source which causes vibrations of the projectile can be determined by analyzing the force situation of the rammer in the stationary state and the state of motion,and next,testing the amplitude and frequency of the position using laser displacement sensor.Finally,the improved scheme was raised to eliminate the impact of the vibration on stability of ramming.
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Jasinski, Marcin, Krzysztof Szczurowski, Adam Wisniewski, Przemyslaw Badurowicz, Tadeusz Bartkowiak, and Norbert Tusnio. "Thermal Energy Analysis of Projectiles during Ricochetting Using a Thermal Camera." Materials 15, no. 13 (July 4, 2022): 4693. http://dx.doi.org/10.3390/ma15134693.
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This paper presents the results of a study of the hazards of ground ignition and/or explosion when various small-calibre projectiles struck various solid materials placed on a test stand in environments at risk of ignition (fire) or explosion (ricochets and projectile penetration of obstacles). For projectile ricochetting tests, the following were used: an armour plate, concrete, sidewalk and granite slabs, etc., and various small-calibre projectiles: 7.62 × 51 mm SWISS PAP, 7.62 × 51T, 7.62 × 51 mm M80, 7.62 × 54R B-32, 7.62 × 54R LPS and .308 Win. Norma Ecostrike. Projectiles impacts were recorded with a high-speed camera (50,400 fps) and thermal cameras (660 fps) and (2615 fps). The ignition capability of solid flammable materials during projectile ricochetting was studied, and the temperatures and surface areas of isotherms were measured as a function of time. From the spherical distribution of thermal energy radiation in space, their volumes, masses of air occupying the studied area, masses of projectile disintegrating into fragments (after impact), thermal energies during projectile ricochetting, histograms of area temperatures and temperatures were calculated. This energy was compared with the minimum ignition energy of the selected gases and liquid vapours, and the ignition temperature were determined. The probabilities of some of the selected gases and liquid vapours which can ignite or cause an explosion were determined. The thermal energies of the 7.62 × 54R B-32 (3400–9500 J) and 7.62 × 51T (2000–3700 J) projectiles ricochetting on the Armox 600 plate was sufficient to ignite (explode) propane−butane gas. The thermal energy of 7.62 × 54R B-32 projectiles ricochets on the non-metallic components (800–1200 J) was several times lower than that of projectiles ricochets on an Armox 600 plate (3400–9500 J). This is due to the transfer of much of the kinetic energy to the crushing of these elements.
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Ding, Chufan, Bin Chen, Weibing Li, Dacheng Gao, Yaohui Chen, and Jun Feng. "A Numerical Study on Projectile Penetration into Underwater Torpedo Warhead." Journal of Physics: Conference Series 2478, no. 7 (June 1, 2023): 072043. http://dx.doi.org/10.1088/1742-6596/2478/7/072043.
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Abstract Underwater torpedo interception could be conducted by shell perforation or even warhead impact detonation with high speed projectiles. This work deals with the projectile water entry and sequent penetration into underwater torpedo whereby both aluminium shell perforation and explosive detonation are numerically studied. The water entry model and aluminum impact model are validated against test data for underwater aluminum shell penetration. Targets are located under water with 20 cm depth where aluminium shells for penetration are air-back while the impact detonation model has explosives inside shell. Four kinds of different nose shape tungsten projectiles are used for penetration simulation, revealing that ogival nose projectiles have superior performance for both shell perforation as well as detonation than conical nose projectiles. Numerical predictions shed some light on nose shape optimization design of high velocity projectile against torpedoes.
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Leśnik, Grzegorz, Małgorzata PAC, and Łukasz SZMIT. "Comparative Analysis of Trajectory of 7.62 × 51 mm Projectiles Fired at Different Initial Velocities." Problems of Mechatronics Armament Aviation Safety Engineering 13, no. 3 (September 30, 2022): 99–112. http://dx.doi.org/10.5604/01.3001.0016.0054.
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The subject of the analysis involves the trajectories of 7.62 mm Lapua Scenar GB432 projectiles and “Ball” lead core projectiles manufactured by MESKO S.A. (Poland) fired at different initial velocities from 16, 20 and 26 inch long barrels. Calculations in the scope of the external ballistics concerning the characteristics of the trajectories of projectile fired from the analysed weapons were made using the PRODAS 3.5 software by Arrow Tech, using a mathematical model of the solid body movements with six degrees of freedom. During the analyses, the phenomena of the internal and transient ballistics and barrel vibrations were not taken into account. The subject of the study was only the trajectory of a projectile fired with a specific initial velocity corresponding to a barrel of a given length. The impact of wind was assessed by modifying the atmosphere model by adding a side wind blowing at a constant velocity throughout the distance. The results allowed the analysis of the effect of the barrel length and the associated initial velocity of the projectile on the nature of the projectile trajectory, especially the obtained overheight path and projectile range. The impact of the side wind on different types of projectiles was also assessed. When shooting precision rifles, it is better to use rounds with heavy projectiles, optimized for long-distance shooting. Lightweight-projectile rounds can be successfully used in the semi-automatic rifles used for support at the lowest levels, where more manoeuvrability (including barrels with a length not exceeding 20 inches) and higher fire rate is required, and, at the same, where shooting at distances exceeding 500 m is not necessary. Lightweight-projectile rounds can also be successfully used for marksmanship training at distances below 500 m, where the differences between the trajectories of different projectiles are the least.
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Zhang, Hao, Haifu Wang, Qingbo Yu, Yuanfeng Zheng, Guancheng Lu, and Chao Ge. "Perforation of Double-Spaced Aluminum Plates by Reactive Projectiles with Different Densities." Materials 14, no. 5 (March 5, 2021): 1229. http://dx.doi.org/10.3390/ma14051229.
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Perforation behavior of 3 mm/3 mm double-spaced aluminum plates by PTFE/Al/W (Polytetrafluoroethylene/Aluminum/Tungsten) reactive projectiles with densities ranging from 2.27 to 7.80 g/cm3 was studied experimentally and theoretically. Ballistic experiments show that the failure mode of the front plate transforms from petalling failure to plugging failure as projectile density increases. Theoretical prediction of the critical velocities for the reactive projectiles perforating the double-spaced plates is proposed, which is consistent with the experimental results and well represents the perforation performance of the projectiles. Dimensionless formulae for estimating the perforation diameter and deflection height of the front plates are obtained through dimensional analysis, indicating material density and strength are dominant factors to determine the perforation size. High-speed video sequences of the perforation process demonstrate that high-density reactive projectiles make greater damage to the rear plates because of the generation of projectile debris streams. Specifically, the maximum spray angle of the debris streams and the crater number in the debris concentration area of the rear plate both increase with the projectile density and initial velocity.
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BORKOWSKI, Jacek, and Eugeniusz MILEWSKI. "EXPERIMENTAL EVALUATION OF 100 MM CHARGE FOR EXPLOSIVELY FORMED PROJECTILE." PROBLEMY TECHNIKI UZBROJENIA 162, no. 4 (March 14, 2023): 7–25. http://dx.doi.org/10.5604/01.3001.0016.3023.
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The construction of 100 mm charge for explosively formed projectile was proposed in the article. The construction of charge was tested on the range. The results of field tests of an explosively formed projectile with the expected design parameters are presented. The accuracy of projectiles hitting the target at 750 calibre distance was determined. The penetration of projectiles was shown on the examples of impact on a 30 mm thick target from rolled homogenous steel. Exemplary shapes of explosively formed projectiles on the flight path in the form of imprints in a paper target are presented. The results of fragmentation of the charge casing were also analysed.
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Odaci, Kutlay, Cenk Kılıçaslan, Alper Taşdemirci, Athanasios G. Mamalis, and Mustafa Güden. "Projectile Impact Testing Aluminum Corrugated Core Composite Sandwiches Using Aluminum Corrugated Projectiles: Experimental and Numerical Investigation." Materials Science Forum 910 (January 2018): 102–8. http://dx.doi.org/10.4028/www.scientific.net/msf.910.102.
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E-glass/polyester composite plates and 1050 H14 aluminum trapezoidal corrugated core composite sandwich plates were projectile impact tested using 1050 H14 aluminum trapezoidal fin corrugated projectiles with and without face sheets. The projectile impact tests were simulated in LS-DYNA. The MAT_162 material model parameters of the composite were determined and then optimized by the quasi-static and high strain rate tests. Non-centered projectile impact test models were validated by the experimental and numerical back face displacements of the impacted plates. Then, the centered projectile impact test models were developed and the resultant plate displacements were compared with those of the TNT mass equal Conwep simulations. The projectiles with face sheets induced similar displacement with the Conwep blast simulation, while the projectiles without face sheets underestimated the Conwep displacements, which was attributed to more uniform pressure distribution with the use of the face sheets on the test plates.
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RUTKOWSKI, Adam, Adam KAWALEC, and Józef JARZEMSKI. "Concept of Short-Range Radar and Counter-Projectile for Detecting and Countering Armour-Piercing Projectiles." Problems of Mechatronics Armament Aviation Safety Engineering 12, no. 2 (June 30, 2021): 55–62. http://dx.doi.org/10.5604/01.3001.0014.9337.
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During warfare and acts of terrorism an extreme threat to vehicles and other high-value assets comes from armour-piercing projectiles. Under these conditions, defence systems should include devices capable of rapid detection of these threats. Defence assets should also be provided with counter-projectile systems capable of destroying incoming armour-piercing projectiles at a safe distance from the asset to be protected. This paper describes the concept of a system comprising of a lightweight short-range radar and a counter-projectile for countering armour-piercing projectiles. The purpose of the radar is to monitor the environment and search for incoming armour-piercing projectiles. When an armour-piercing projectile is detected in a designated monitoring area, an automatic command is given for the counter-projectile launcher to be fired. The counter-projectile deployed can be equipped with a single or multi-sensor detection head unit and an explosive payload module, both being the primary components of the warhead. When the signal analysis blocks interfaced with the detection head determine that the armour-piercing projectile to be struck down is in the target position in relation to the counter-projectile deployed, they automatically command the explosive payload module to detonate. The components of the system concept were tested in proving ground conditions. The successful results of these tests confirmed the validity of the solutions initially adopted and the execution of the individual systems.
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Song, Mei Li, Xiao Ming Wang, and Wen Bin Li. "Study on the Dimensionless Model of High-Speed Penetration Efficiency." Applied Mechanics and Materials 789-790 (September 2015): 362–67. http://dx.doi.org/10.4028/www.scientific.net/amm.789-790.362.
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Penetration efficiency reflects high speed projectile penetration ability with the impact velocity (>800m/s) variation. To further study the penetration efficiency engineering model, the physical and mechanical parameters that affect the penetration efficiency of high-speed projectiles penetrating into concrete target are analyzed, penetration efficiency dimensionless quantities are determined, such as projectile’s length to diameter ratio, projectile and target strength ratio, etc. The dimensionless equation of penetration efficiency is got by using the homogeneous principles of the laws of physics dimensionless. According to experimental data, a function of dimensionless penetration efficiency and dimensionless projectile speed is fitted. Finally, the model is verified by test, and the model calculations and experiment results agree well. The model obtained in this paper can estimate the projectile’s impact velocity when the penetration efficiency reaches the maximum, it would be a theoretical guidance for high speed penetration effects experiments.
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Zhong, Yang, and Liang Ming Wang. "Numerical Simulation of Projectile Accelerating Process in Aftereffect Period." Applied Mechanics and Materials 236-237 (November 2012): 576–80. http://dx.doi.org/10.4028/www.scientific.net/amm.236-237.576.
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The initial velocity of a projectile has great effects on the weapon performances and it influences firing accuracy. It is meaningful to know the motion of projectiles in after-effect period. This article studies the motion of the projectile by using a Six Degrees-of-Freedom rigid model and chimera method, which is suitble to simulate large-scale deplacemengt of projectiles. The results of the simulation show that the velocity of the projectile increases rapidly first and decreases slowly after reaching the peak value.
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Gao, Jianguo, Zhihua Chen, Wei-Tao Wu, and Xin Li. "Numerical Investigations on the Water Entry of Cylindrical Projectiles with Different Initial Conditions." Applied Sciences 9, no. 9 (May 6, 2019): 1858. http://dx.doi.org/10.3390/app9091858.
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In this paper, coupled with Reynolds-averaged Navier–Stokes equations and ballistic equations, the numerical simulations of high-speed water entry of projectiles under different conditions have been conducted. The water-gas flow was modeled by the mixture multiphase model. The numerical results indicated that the simulations agree well with analytical solutions by two cavity models, which validates the model applied. Then the effects of variations of project length, entry angle and velocity on the entry process of projectiles were further investigated. The results show that, for small water entry angles, the cavity wall interacts with the projectile, affects the trajectory of the projectile, and even ricochets for projectiles with small length (5D). On the other hand, the projectile vibrates during the whole process of water entry; the vibration amplitude decreases with the increase of projectile length and entry angle; however, it is the contrary for the vibration period. Furthermore, after the initial impact period, the influence of these parameters on the drag coefficient is not obvious.
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Zhang, Lite, Zhuokai Wang, and Huixia Jia. "Effect of Wave Phases and Heights on Supercavitation Flow Field and Dynamic Characteristics of Successively Fired High-Speed Projectiles." Journal of Marine Science and Engineering 11, no. 3 (March 16, 2023): 629. http://dx.doi.org/10.3390/jmse11030629.
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The study of the water entry of successively fired projectiles under a wave environment is of great significance for the development and application of supercavitation weapons. In this paper, the supercavitating flow field of two successively fired projectiles entering water under different wave conditions is numerically simulated by the volume of the fraction model considering the cavitation of water. The motion of projectiles is handled by the overlapping grid technology and the simulated projectiles have six degrees of freedom. The effects of different wave phases and wave heights on the supercavitating flow field and the dynamic loads of the projectiles are studied. The research results show that the wave phase has an effect on the evolution and size of the supercavitation and the effect of the wave phase on the water splash above the free surface is more obvious. The peak of the drag force of the first projectile under conditions of different wave phases with 0.12 m wave height can be reduced by about 50% compared with that under the no-wave condition. The wave phases have an effect on the peak of the drag coefficient, and for the first projectile the peak under the condition of the 180° phase is about 40% lower than that of the 0° phase. The peak of the drag coefficient of the first projectile decreases with the increase in wave height. When the wave height increases from 0.0 m to 0.05 m, the peak value decreases by about 45%. For all conditions, regardless of wave phases or wave heights, the peak of the drag coefficient of the second projectile is obviously much lower than that of the first projectile. Accordingly, the decrease in the velocity of the second projectile is far slower than that of the first one. Negative values of the drag coefficient on the second projectile are observed when the second projectile enters the cavity of the first one.
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Zhang, Dingye, Jun Guan, Wenjun Yi, Youran Xia, and Kangjian Wang. "Wind Identification of Spinning Projectile Using Improved Multiobjective Differential Evolution Algorithm." International Journal of Aerospace Engineering 2022 (September 12, 2022): 1–13. http://dx.doi.org/10.1155/2022/9726595.
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Wind velocity has an important influence on the ballistic characteristics of uncontrolled projectiles. It is difficult to precisely determine the projectile’s impact position if wind velocity information from the projectile’s flight process cannot be collected. A wind velocity identification technique of spinning projectile based on the multiobjective chaotic adaptive differential evolution algorithm is suggested to increase the estimation accuracy of wind velocity and ballistic prediction accuracy during projectile flight. The variation law of projectile aerodynamic characteristics under no wind situation is calculated using the 4D kinematic model of spinning projectile. Three aerodynamic parameter coefficients are chosen as reference variables, three objective functions are defined by mean square error, and the two components of wind velocity along the ground coordinate system are used as decision variables in the identification process. The study identifies the two components, which is based on the multiobjective chaotic adaptive differential evolution algorithm. Several groups of wind velocity identification under constant and variable wind conditions are numerically simulated. The results show that the suggested method can estimate wind velocity effectively and precisely throughout the flight of spinning projectile.
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Batuev, Stanislav P., Viktor V. Burkin, Aleksey S. D'yachkovskiy, Aleksandr N. Ishchenko, Pavel A. Radchenko, Andrey V. Radchenko, and Anton Yu Sammel. "Analysis of the effect of driving belts on the interaction between elongated projectiles and light alloy barriers." Vestnik Tomskogo gosudarstvennogo universiteta. Matematika i mekhanika, no. 89 (2024): 66–76. http://dx.doi.org/10.17223/19988621/89/5.
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To assess the effect of a driving belt on the elongated projectile penetration into a barrier, it is necessary to perform mathematical modeling considering all the physical and mechanical properties of the projectile and barrier. Using the modified EFES software package, the high-speed interaction of elongated steel projectiles with aluminum barriers is calculated in the speed range of 200 – 450 m/s. Two configurations of the projectile, namely, the projectiles with and without belts, are studied numerically. The developed mathematical model is validated using experimental results for the high-speed interaction of elongated projectiles with aluminum barriers. A comparison of the calculated and experimental results yields a discrepancy in the behind-the-barrier speed, which does not exceed 9.5%. The obtained data show an insignificant influence of the driving belts on the behind-the-barrier speed; the difference in the values is less than 4%.
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Величко Лев Дмитрович, Горчинський Ігор Володимирович, and Сорокатий Микола Іванович. "ЗОВНІШНЯ БАЛІСТИКА СНАРЯДУ БМ1 ВИПУЩЕНОГО З Т-12 (МТ-12)." World Science 1, no. 1(53) (January 31, 2020): 23–29. http://dx.doi.org/10.31435/rsglobal_ws/31012020/6891.
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The magnitudes of the kinematic parameters of projectiles motion in the air depends on deterministic (form of projectile, its mass, temperature of air and charge, atmospheric pressure, derivation) and nondeterministic (muzzle velocity, magnitude and direction of wind velocity) values. During the projectile movement, its weight and frontal air resistance force have a determining influence on its dynamics. In the article it is investigated proposed by authors the mathematical model of determination of the functional dependence of the magnitude of the frontal air resistance force of the projectile’s motion on its velocity, mass and caliber, geometric characteristics, temperature and density of air, atmospheric pressure, sound speed in air. Since the trajectory of movement of the BM1 projectile released from the T-12 (MT-12) is canopy, it is assumed that during the projectile’s flight the air temperature and atmospheric pressure are unchanged and equal to their value at the point of the gun.
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Yuan, Xin, Zijie Zhao, Biaojun Zhou, and Qi Dai. "Numerical Simulation of Cavitation and Hydrodynamic Characteristics of Supercavitating Projectiles in the Shear Flow." Journal of Physics: Conference Series 2478, no. 11 (June 1, 2023): 112027. http://dx.doi.org/10.1088/1742-6596/2478/11/112027.
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Abstract To investigate the cavitation and hydrodynamic characteristics of supercavitating projectiles in the shear flow, the Mixture multiphase and Schnerr-Sauer cavitation models are employed to simulate the underwater projectiles. The inflow average velocity is 600 m/s, and the shear rates range from 0 to 7500 s−1. In the uniform flow, the supercavity enveloping projectiles is vertically symmetrical. The drag is dominated by pressure drag, and the lift coefficient is 0. However, the supercavity is asymmetric in the shear flow, which deviates towards the low-speed side of projectiles. This is because the flow around projectiles runs faster on the high-speed side, and the vortices on the low-speed side entrain more fluid from the high-speed side. Thus, the projectiles suffer from normal shear stress orientating towards the low-speed side, and the lift coefficient turns negative. When the shear rate further increases, the projectile shoulder contacts water on the high-speed side, and the viscosity around projectiles is enhanced, resulting in the significant augmentation of the drag coefficient. As the water pressure is strongly larger than saturated vapor pressure on the low-speed side, the normal component of pressure acts more intensely towards the low-speed side of projectiles, and the lift coefficient is further decreased.
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DZIOPA, Zbigniew, and Krzysztof ZDEB. "Effect of the Man-Weapon System on the Trajectory of a Projectile Fired from a Machine Pistol." Problems of Mechatronics Armament Aviation Safety Engineering 8, no. 1 (March 31, 2017): 101–14. http://dx.doi.org/10.5604/01.3001.0009.8997.
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The process of burst-firing two projectiles from a Skorpion vz. 61 7.65 mm calibre machine pistol was recorded during a test at a firing range operated by the Polish Police. This experimental test involved Browning 7.65 x 17 mm SR ammunition rounds. The shots were fired by a Police Special Forces operative. The shots were recorded with a Phantom v.9.1 slow-motion video camera, complete with the essential accessories. TEMA, a software suite dedicated to video recording analyses, was used to determine the initial kinematic parameters of flight for each of the two projectiles. By applying the theorem of momentum and spin change, a theoretical projectile flight model was developed with a respective simulation runtime in SciLab. The projectile flight results were verified with the experimental test results to validate the developed model. Having delivered a reliable projectile flight model, an analysis was carried out to study the effectiveness of the shots fired by the Police Special Forces operative towards a target 30 metres away. This paper presents a determined process of burst firing of two projectiles. It is also a representative example of repetitive shooting. The ultimate task of this research is to develop guidelines for the design of machine pistol dynamic properties that reduce the scatter of projectiles shot in series.
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Huang, Chuang, Zhao Liu, Zixian Liu, Changle Hao, Daijin Li, and Kai Luo. "Motion Characteristics of High-Speed Supercavitating Projectiles Including Structural Deformation." Energies 15, no. 5 (March 7, 2022): 1933. http://dx.doi.org/10.3390/en15051933.
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High-speed supercavitating projectiles receive tremendous hydrodynamic force when flying underwater in tail-slap mode, and have obvious structural deformation and structural vibration. To study the motion characteristics of high-speed supercavitating projectiles, a bidirectional fluid-structure interaction model was established, and validated by comparing with the existing results. The motion, supercavitation flow field, and structural deformation response process of a supercavitating projectile were numerically investigated under the conditions of initial speed within 800–1600 m/s. It was found that the tail-slap motion of high-speed supercavitating projectiles is correlated with a high-frequency structural vibration. Further, the amplitude of the structural vibration increases with the initial speed. When flying with an initial speed higher than 1200 m/s, supercavitating projectiles encounter a great structural deformation under the action of the huge hydrodynamic load, which exerts a significant influence on the motion characteristic, and even destroys the trajectory stability. Thus, the supercavitating projectile cannot be regarded as a rigid body any more, and the structural response effect must be considered.
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Chen, Pengcheng, Weijing Niu, Xiaopeng Yan, and Guoyun Lu. "Theoretical model for dynamic response of aluminum foam sandwich targets by truncated cone-nosed projectiles." Journal of Sandwich Structures & Materials 20, no. 2 (August 12, 2016): 249–67. http://dx.doi.org/10.1177/1099636216664288.
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Based on classical dynamic cylindrical cavity expansion theory, a nine-step penetration and perforation process of aluminum foam sandwich targets by truncated cone-nosed projectiles are developed theoretically. In the theoretical model, the friction, shear strength, and the force for tearing the cells in the core at the periphery of the projectile are considered, and the resistance force and instantaneous velocity are achieved from this process. On this basis, the effects of the geometry of projectiles, core thickness, and impact velocities of projectiles on absorbed energy are also analyzed. Simple composite failure criteria will be applied in the fracture and perforation of the face sheet, core, and back sheet. It is shown that the diameter of projectile and core thickness have significant influence on the ballistic velocity of the projectile, which is important for the impact response and absorbed energy of the sandwich. Numerical simulation at various impact velocities is also performed, and there is a good agreement between the numerical predictions and the analytical measurements.
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Fujiwara, A., T. Kadono, A. Nakamura, T. Ishibashi, and N. Fujii. "Penetration of Hypervelocity Projectiles into Low Density Materials." International Astronomical Union Colloquium 126 (1991): 281–84. http://dx.doi.org/10.1017/s0252921100066963.
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AbstractSpherical nylon projectiles of 7mm diameter and up-to 4km/s velocities were penetrated into three types of targets; aluminum multisheet stacks, foamed polystyrene, and 1-atm air. Penetration depth, recovery rate of the projectiles were determined as a function of projectile velocity and target density, and a new type of dust collector is proposed.
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Luo, Qiao, and Xiaobing Zhang. "Numerical simulation of gas-solid two-phase reaction flow with multiple moving boundaries." International Journal of Numerical Methods for Heat & Fluid Flow 25, no. 2 (March 2, 2015): 375–90. http://dx.doi.org/10.1108/hff-01-2014-0018.
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Purpose – In engineering applications, gas-solid two-phase reaction flow with multi-moving boundaries is a common phenomenon. The launch process of multiple projectiles is a typical example. The flow of adjacent powder chambers is coupled by projectile’s motion. The purpose of this paper is to study this flow by numerical simulation. Design/methodology/approach – A one-dimensional two-phase reaction flow model and MacCormack difference scheme are implemented in a computational code, and the code is used to simulate the launch process of a system of multiple projectiles. For different launching rates and loading conditions, the simulated results of the launch process of three projectiles are obtained and discussed. Findings – At low launching rates, projectiles fired earlier in the series have little effect on the launch processes of projectiles fired later. However, at higher launching rates, the projectiles fired first have a great influence on the launch processes of projectiles fired later. As the launching rate increases, the maximum breech pressure for the later projectiles increases. Although the muzzle velocities increase initially, they reach a maximum at some launching rate, and then decrease rapidly. The muzzle velocities and maximum breech pressures of the three projectiles have an approximate linear relationship with the charge weight, propellant web size and chamber volume. Originality/value – This paper presents a prediction tool to understand the physical phenomenon of the gas-solid two-phase reaction flow with multi-moving boundaries, and can be used as a research tool for future interior ballistics studies of launch system of multiple projectiles.
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Rodríguez-Millán, Marcos, Antonio Díaz-Álvarez, Richard Bernier, María Henar Miguélez, and José Antonio Loya. "Experimental and Numerical Analysis of Conical Projectile Impact on Inconel 718 Plates." Metals 9, no. 6 (June 2, 2019): 638. http://dx.doi.org/10.3390/met9060638.
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This paper analyses the impact behavior of Inconel 718 through experimental and numerical approach. Different conical projectiles were tested in order to obtain the ballistic curves and failure mechanisms. A three-dimensional (3D) numerical model corresponding to the experimental tests was developed using the Johnson–Cook constitutive model. The experimental data (residual velocities, global, and local perforation mechanisms) were successfully predicted with the numerical simulations. The influence of the projectile’s nose angle was found to be important when designing ballistic protections. The projectile with the narrowest angle, 40°, developed a ballistic limit approximately 10 m/s lower than the projectile with a 72° nose. The use of double-nose projectile for the same nose angle, 72°, led to a ballistic limit 12 m/s lower than that obtained for the single nose.
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Hathaway, Alan F., and John R. Burnett Jr. "Sabot Front Borerider Stiffness vs. Dispersion: Finding the Knee in the Curve." Shock and Vibration 8, no. 3-4 (2001): 193–201. http://dx.doi.org/10.1155/2001/296752.
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In the design of armor piercing, fin-stabilized, discarding sabot projectiles, the radial stiffness of the sabot front borerider has a significant impact on the projectile's dispersion and is, therefore, an important design consideration. Whether designing a new projectile or trying to improve an existing design, projectile designers can achieve front borerider stiffness without understanding its affect on dispersion characteristics. There is a knee in the stiffness vs. dispersion curve at which a change in the sabot front borerider stiffness will have a significant impact on dispersion or no impact at all depending on whether the stiffness is increased or decreased. The subject of this paper is an analytical approach to quantitatively determine the knee in the curve. Results from using this approach on the M865 APFSDS projectile are also presented.
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Mayboroda, Oleksandr, and A. Derepa. "Planing of the Finite Aspect Ratio Plate at Subsonic, Transonic and Supersonic Speeds." Advances in Military Technology 18, no. 2 (October 27, 2023): 179–94. http://dx.doi.org/10.3849/aimt.01800.
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The mechanics of underwater supercavitating projectiles are currently being extensively researched. The disadvantage of such projectiles is their movement instability. There is a proposal to use stern planing plates to stabilize projectile’s movement. However, the hydrodynamic characteristics of planing plates are known only for low subsonic speeds. This article describes a load study on a planing plate at subsonic, transonic and supersonic speeds with detached and attached shock waves. The obtained calculation results of normal forces satisfactorily agree with the known theoretical solutions and experimental data and can be used to calculate the motion stabilization of supercavitating underwater projectiles with planing stern plates.
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Pinto, Laís, Alan Motta do Canto, José Vital Filho, and Ronaldo Rodrigues de Freitas. "Treatment of a Penetrating Intraorbital Injury by Rubber Projectile." Craniomaxillofacial Trauma & Reconstruction Open 1, no. 1 (January 2017): s—0037–1604033. http://dx.doi.org/10.1055/s-0037-1604033.
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Penetrating injuries caused by rubber projectiles are classified as low-velocity injuries. When the midface is affected, these can cause fractures, eye injuries, and even blindness. Unlike conventional projectiles, the removal of rubber projectiles involving the orbit and correction of associated fractures are mandatory for preventing infection and anophthalmic orbit syndrome, which is characterized by enophthalmos of the prosthesis, superior sulcus depression, and lower eyelid ptosis. This article aims to describe a case of penetrating injury by rubber projectile, associated with the removal and late reconstruction of the orbital walls, and to show the results obtained.
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Bilar, Adam, Paweł Boguszewicz, and Witold Perkowski. "Gravelling Test for Rail Windshield." Journal of KONES 26, no. 1 (March 1, 2019): 7–15. http://dx.doi.org/10.2478/kones-2019-0001.
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Abstract During preliminary tests of locomotive windshield resistance to gravelling, according to the applicable standard PN-EN 15152:2007, carried out in the Institute of Aviation, the problem of the projectile overturning after leaving the cannon barrel was detected. Three tests recorded with a high-speed camera are presented in this article. This problem was found to be due to the incorrect projectile geometry. In order to stabilise the trajectory of the projectile, four types of projectiles were made using military experience. All of them meet relevant test conditions from the point of view of the test piece (locomotive windshield). The best projectile modification was obtained in the tests with an average deviation of the expected impact angle of 11° compared to 75° for a projectile made exactly according to the guidelines of the standard. Each of 22 modified projectiles hit the test piece with the tip, while out of the 12 original projectiles only 4 hit the test piece with the tip. The impact test results confirm that it is possible to perform a gravelling test according to the standard concept, but it seems necessary to clarify the standard requirements and to modify the projectile shape. The article contains a proposal for the projectile modification and highlights inaccuracies in the standard concerning the gravelling test.
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Гузик, Н. М., Н. Б. Сокульська, and Л. Д. Величко. "Mathematical model of external ballistics of projectiles." Системи обробки інформації, no. 1 (172) (May 14, 2023): 20–28. http://dx.doi.org/10.30748/soi.2023.172.03.
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The paper presents mathematical model of external ballistics of projectile, fired from cannon. The drag force has a decisive influence on the dynamics of the projectile. Direct calculation of the functional dependence of the drag force on the set of parameters is quite controversial and has not been utilized so far. Therefore, the author calculus the functional relativity, approximately, solving the inverse problem of mechanics. The flight range of a projectile at certain aiming angles, noted in the firing tables, determine the drag force according to the effect on a projectile of its weight and Coriolis force. Its functional dependence is described separately at the stages of projectile’s motion with supersonic, transonic and subsonic velocities. Due to the functional dependence of the drag force of a projectile, the influence of a charge projectile, initial velocity, atmospheric pressure, air temperatures and projectile’s mass effect on kinematic parameters of its motion can be calculated. Knowledge of this dependence of the drag force of the projectile’s movement allows to automate, using appropriate software, the determination of the elevation angle depending on the location of the target and the values of deterministic and nondeterministic factors.
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Nie, Xiaodong, Xiangyun Wu, Zhi Yi, Zhilin Long, Hui Zhou, and Nan Ji. "Discussion on Static Resistance of Granite under Penetration." Materials 16, no. 9 (April 25, 2023): 3353. http://dx.doi.org/10.3390/ma16093353.
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A total of 9 tests were carried out with 30 mm and 78 mm caliber scaled projectiles penetrating into granite targets. The penetration depth, crater diameter, and mass loss rate were examined and discussed. The results indicate that the dimensionless penetration depth of large-caliber projectiles is 20% greater than small-caliber projectiles. Based on the description of static resistance Ra in the Forrestal semi-empirical formula, the size effect of dimensionless penetration depth can be attributed to the size effect of static resistance Ra, and it can be seen that the penetration static resistance of projectile A is 40% higher than that of projectile B. Numerical simulations of projectile penetration into granite targets were conducted using the finite element program ANSYS/LS-DYNA. In terms of penetration depth and crater damage, the numerical simulation results agree well with the test data. This suggests that the selection of parameters was reasonable. The influence of compressive strength, projectile striking velocity, mass, diameter, and caliber–radius–head (CRH) ratio on the static resistance Ra were studied by RHT model parameterization. Based on the numerical results from the parametric study, an empirical formula was derived to predict the static resistance Ra.
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Kraus, Alexander E., Evgeny I. Kraus, and Ivan I. Shabalin. "Simulation of a Group Impact on a Heterogeneous Target of Finite Thickness." Journal of Siberian Federal University. Mathematics & Physics 14, no. 6 (December 2021): 700–711. http://dx.doi.org/10.17516/1997-1397-2021-14-6-700-711.
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Numerical simulation of the processes of high-speed loading of homogeneous and heteroge- neous targets by single projectiles, as well as by a group of projectiles with the same parameters in mass and momentum, has been carried out. Based on a comparison of the numerical simulation results for loading targets with different sets of projectiles, it is found that a projectile in the form of a ring knocks out the maximum hole in the target in terms of geometric dimensions, while a set of seven small disks removes the maximum mass from the target. The ring impact forms a continuous spall plate, which outruns the cloud of fragments of the destroyed material. Adding more than 5% of ceramics to the aluminum target volume does not allow the projectiles to penetrate through
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Li, Gan, Chunming Song, and Mingyang Wang. "Evolution of penetration mechanism induced by strain rate effect." EPJ Web of Conferences 183 (2018): 01063. http://dx.doi.org/10.1051/epjconf/201818301063.
Full textAbstract:
According to the dynamic mechanical properties, in the striking velocity range, the strain rate of the projectile and target caused by penetration can reach 104~106 /s. The strain rate effect increases sharply and then tends to saturation. During the penetration process, the mechanical properties of the target and the projectile change violently and present serious spatial inhomogeneity, which has a great influence on the penetration effect. In this paper, penetration experiments of granite targets by steel projectiles are carried out in the range of 1200m/s~2400m/s, the crater parameters are measured and the projectiles are recovered to obtain the macroscopic failure pattern of the projectiles and the targets. Based on the dynamic mechanical properties, an interaction model of the projectiles and the target is established, which considers the spatial and temporal distributions of the strain rates during penetration. With this model, the influences of material mechanical behaviour on penetration effect at different velocities are analysed, the formation cause and internal mechanism of penetration effect are discussed, and the influence mechanism of the strain rate effect on the penetration mechanism evolution is also revealed.
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Ren, Kai, Shunshan Feng, Zhigang Chen, Taiyong Zhao, Likui Yin, and Jianping Fu. "Study on the Penetration Performance of a 5.8 mm Ceramic Composite Projectile." Materials 14, no. 4 (February 4, 2021): 721. http://dx.doi.org/10.3390/ma14040721.
Full textAbstract:
The penetration ability of a 5.8 mm standard projectile can be improved by inserting a ZrO2 ceramic ball with high hardness, high temperature, and pressure resistance at its head. Thereby, a ceramic composite projectile can be formed. A depth of penetration (DOP) experiment and numerical simulation were conducted under the same condition to study the armor-piercing effectiveness of a standard projectile and ceramic composite projectile on 10 mm Rolled Homogeneous Armor (RHA) and ceramic/Kevlar composite armor, respectively. The results show that both the ceramic composite and standard projectiles penetrated the armor steel target at the same velocity (850 m/s). The perforated areas of the former (φ5 mm & φ2 mm) were 2.32 and 2.16 times larger, respectively, than those of the latter. The residual core masses of these two projectiles (φ5 mm & φ2 mm) were enhanced by 30.45% and 22.23%. Both projectiles penetrated the ceramic/Kevlar composite armor at the same velocity (750 m/s). Compared with the standard projectile, the residual core masses of the ceramic composite one (Ø5 mm & Ø2 mm) were enhanced by 12.4% and 3.6%, respectively. This paper also analyzes the penetration mechanism of the ceramic composite projectile on target plates by calculating its impact pressure. The results show that the ceramic composite projectile outperformed the standard projectile in penetration tests. The research results are instructive in promoting the application of the ZrO2 ceramic composite in an armor-piercing projectile design.
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Jia, Huixia, Rishan Xie, and Yangjie Zhou. "Experimental Investigation of the Supercavitation and Hydrodynamic Characteristics of High-Speed Projectiles with Hydrophobic and Hydrophilic Coatings." Fluids 7, no. 12 (November 23, 2022): 363. http://dx.doi.org/10.3390/fluids7120363.
Full textAbstract:
Supercavitation technology has important application value in military and national defence fields because of its huge potential in drag reduction, while the cavitation around underwater moving objects may be affected by the surface properties of objects. In this paper, the supercavitation characteristics and hydrodynamics of a projectile with hydrophobic and hydrophilic surface coatings were experimentally studied using a high-speed camera. The supercavitation evolution, cavitation size, velocity change, drag force coefficient, and ballistic deflection of projectiles in different water depths are compared and analyzed. The results show that the length and diameter of the supercavity increase with the decrease in water depth. At the same water depth and cavitation number, the length and diameter of the supercavitation of the projectile with hydrophobic coating were greater than those of the projectile with hydrophilic coating, and the drag force coefficient of the hydrophobic projectile was obviously smaller than that of the hydrophilic projectile. Under the working conditions of 6.67D, 16.7D, and 33.3D, the drag force coefficient of the hydrophobic projectile could be reduced by about 20–40% compared with that of the hydrophilic projectile. The maximal reduction in drag force coefficient was up to 40% at σ = 0.34 under a water depth of 33.3D. The velocity attenuation of hydrophobic projectile was about 20% slower than that of hydrophilic projectile. In addition, the ballistic stability of hydrophobic coated projectiles was better than that of hydrophilic coated projectiles in the different water depths observed in the paper.