Ballistic Simulation Research Articles

The Study of Optimal Design for Interior Ballistics Based on the Reducing Barrel Erosion

Aiming at the problem that the effect of barrel erosion is rarely used as a quantitative constraint in the past interior ballistic design process, the optimization design has been done for a large-caliber gun to improve the barrel life of gun and improve the performance of the interior ballistic, and the equivalent full charges (EFCs) is completed by combining different barrel erosion models with the interior ballistic model. The interior ballistic optimization design simulation represented by the minimization of barrel ablation has realized the optimization of the interior ballistic parameters with the reduction of barrel ablation as the constraint, and obtained the interior ballistic scheme that not only meets the interior ballistic performance indicators, but also helps to reduce the ablation of barrel. The research method formed can guide the design of low-ablation interior ballistic schemes for large-caliber gun, which plays an important role in improving the life of barrel.

Equivalent simulation test method for internal ballistics of fuze reserve chemical power source with adjustable combined overload and rotational speed

To solve the problem that the test environment is not equivalent to the actual use environment in the step-by-step test method of fuze reserve chemical power supply, this paper proposes a fuze reserve chemical power source with an adjustable combination of overload and rotational speed by building a test platform to realize the synchronization of overload and rotational speed. In this method, compressed air and a rotary table were used to generate the flight power and rotational speed of the test tool, and then the overload and centrifugal force were controlled and loaded by the tool launcher and damping generator, and finally, the non-destructive recovery of the test tool was realized by the slow release mechanism. The test results showed that using the synchronous realization and controllable combination of overload and rotation, the internal ballistic equivalent simulation method could generate 3 000g ~ 30 000g overload, and the rotational speed of 0 ~ 18 000rpm could be synchronously controlled. The test results of the fuze power supply showed that the combination of overload and rotational speed could be controlled by this method. Under the same conditions, the overload repeatability reaches 95.5%, the rotational speed stability reaches 99.7%, and the equivalence with the medium and large-caliber inner ballistic environment is 91%. Therefore, through the test, the basic equivalent simulation of the ballistic environment in the fuze power supply has been realized.

Research on the Internal Relationship Between Dynamic and Static Combustion Laws of Propellant for a Large-caliber Artillery

In this paper, according to the closed bomb test results of the same formula and different batches of propellant, the static combustion law of the propellant is obtained. Combined with the results of the artillery firing test, the dynamic combustion law of the propellant is obtained through the internal ballistic simulation fitting. The relationship between the static and dynamic combustion laws of the same formula and different batches of propellants is obtained. Using the research results of this paper, for the new batch of propellant, the dynamic combustion law of the new batch of propellant can be determined according to the closed bomb test results. Combined with the internal relationship between the dynamic combustion law and the static combustion law in this paper, the internal ballistic performance prediction accuracy can be improved.

Numerical modelling of heat transfer and simulation of a 5.56 mm rifle barrel

Numerical simulations tend to be useful to have a deep knowledge of phenomena difficult to be observed. In this context, the heat transfer in a 5.56 mm rifle barrel was modelled, simulated and analysed, coupling the Baer-Frankle interior ballistics approach with one and two-dimensional unsteady heat diffusion numerical models. The heat transfer coefficient correlation was obtained using Sutherland approximation of diffusive transport coefficient and output data from PRODAS interior ballistics simulation software. The one-dimensional heat transfer model was solved in MATLAB® environment while the two-dimensional heat transfer model was solved in COMSOL Multiphysics and Simulation Software. The results were verified, providing discrepancies minor than 7% in relation to reference data.

A magnetic field constrained type of multi-barrel common-rail railgun

Adopting the simultaneous launch mode of small and medium caliber railgun is an important means to increase the firepower density, improve the hit probability and strike efficiency. Based on this requirement, this paper creatively proposed a new multi-barrel simultaneous launch EM railgun, named magnetic field constrained type of multi-barrel common-rail railgun. The basic idea is to integrate multiple single-turn rail launchers with a specific structure into one launcher, and “merge” one rail of each single-turn rail launcher with a tight structure combination and arrange it in the center to form the “common rail” of multi-barrel launcher. The other rail of each rail launcher is evenly distributed around the “common rail” in the form of petals, forming the “outer rail” of each rail launcher. “Common rail” and all “outer rails” together form a multi-barrel rail launcher. With the increase of the number of barrels, the current of each barrel is superimposed many times in the common-rail, which greatly improves the magnetic induction intensity of the inner bore, thus improving the launching efficiency of the system. In order to overcome the problem of high magnetic induction intensity near the common-rail and low magnetic induction intensity near the external rail caused, a magnetic field constrained structure is added to the external rail to form a magnetic field constrained type of multi-barrel common-rail railgun. The basic structure of electromagnetic railgun with different number of barrels is simulated, and the spatial distribution characteristics of magnetic field are analyzed. Based on the magnetic field analysis, the interior ballistic simulation of the multi-barrel common-rail railgun is carried out, and the interior ballistic characteristics and launching efficiency of various numbers of barrels are analyzed. The simulation results show that the magnetic field constrained type of multi-barrel common-rail railgun can effectively improve the magnetic induction intensity near the external rail, improve the uniformity of the magnetic induction intensity distribution in the inner bore, and improve the inductance gradient, thus increasing the system efficiency. The structure of the multi-barrel common-rail railgun provides a new idea for the engineering application of the multi-barrel simultaneous launch mode.

A fast calculation model for interior ballistics simulation of a recoilless launch system with high chamber pressure

Recoilless launch system is economical and convenient. This paper provided a recoilless launch system with high chamber pressure based on the theory of recoilless gun. A program for interior ballistics simulation of the launch system based on the mixed propellent was designed. The curves of chamber pressure and projectile velocity on time and projectile travels were provided by the program. And the phenomena of different combustion stages presented by the curve are discussed. The simulation results reached the set indicators, and it was consistent with the actual interior ballistics. The designed model has certain reference value for real-time simulation and fast computation.

Combining protective clothes with human body models for finite element ballistic impact simulations

The ballistic deformation of an ultra-high-molecular-weight (UHMW) polyethylene (PE) composite has been subjected numerically to a multi-layered soft ballistic fabric package modelled upon the body contours of the Global Human Body Models Consortium (GHBMC) human body models M50-P and F05-P. The results of the clothing-body-interaction have been investigated and compared to the behavior of anthropomorphic surrogate models made from ballistic clay. For building the fabric model in donned shape, a single ply of woven fabric material has been converted upon the anthropomorphic body contour by subjecting it to a quasi-deep drawing process. After the fabric deformation, the shaped layer was duplicated 20 times and shifted outwards to build the fabric model, representing a multi-layered soft ballistic fabric package. The results of the ballistic impact simulation show that the response of the human body models (HBMs) is much more compliant than the behavior of the surrogate models. The deformation of the female HBM in terms of penetration depth and diameter of the affected impact region is slightly more severe than the deformation of the male counterpart with respect to identical impact conditions.

Teaching Sprinkler Irrigation Engineering by a Spreadsheet Tool

Since being released 40 years ago, computer spreadsheets have proven to be worthwhile for use in educational contexts. There is plenty of evidence for this in practically every scientific discipline and engineering field. In view on this fact, the present work exposes a didactical resource, named the sprinkler irrigation tool, developed in Excel® spreadsheet licensed by 2018 Microsoft©. The objective of this tool is to offer an alternative to students in irrigation engineering, particularly for those training in the design of sprinkler irrigation systems so they can develop their theoretical knowledge and practical skills acquired in laboratory and field experiments. The main findings reported in this paper address well-agreed methodologies for evaluating radial patterns of precipitation rates, diameter distribution frequency, ballistic simulation of water drops’ movement through air, kinetic energy, and performance indicators as part of the core parameters of efficient irrigation system management. This computing tool provides outcomes in tabular and graphical formats that are consistent with those found in studies previously published in specialized literature on related topics. Likewise, spreadsheets have been proven to be adequate pedagogical instruments on the path to achieving meaningful learning; however, this assertion still needs to be confirmed through a rigorous study of students who have used the developed tool.

Ballistic Simulation and Analysis of Turntable Rotation on the Flight Stability of Anti-aircraft Rocket

The air defense multiple launch rocket is an effective terminal air defense weapon. The rotation of its turntable has an effect on the rocket’s ballistic. In the paper, the rotation angular velocity of the turntable is combined into the initial swing angular velocity of the transverse and longitudinal axis of the projectile axis. Based on this, taking the rotation of the turntable in the direction as an example, the six-degree-of-freedom rigid body ballistic model is selected for full ballistic simulation, and the stability of the projectile flight at different rotation angular velocities is studied according to the simulation results of the rocket attitude angle.

Research on the Interior Ballistic Design of a Low Impact Ejection Explosive Bolt

Aiming at the comprehensive functional requirements of the connection, unlocking, boosting and impact reduction of the pyrotechnic separation device, a low impact ejection explosive bolt was designed, and its action process was analyzed. The internal ballistic simulation program is used to analyze and study the matching characteristics of internal ballistic input parameters and output parameters. The verification shows that the design is reasonable and accurate. This study provides a reference for the design of similar low impact ejection explosive bolt.

Evaluation of automatic versus material test-based calibrations of concrete models for ballistic impact simulations

Concrete is used for protective structures all over the world. Accurate response estimates to a given threat is vital for designing such structures. Concrete models often require numerous input parameters for which sufficient experimental data can be challenging to obtain. Some models are accompanied by parameter generators which use the unconfined compression strength to extrapolate the remainder of the parameters based on experimental databases. This study investigates simulation of ballistic impact on high-strength concrete with 75 MPa nominal unconfined cylindrical compressive strength. The first objective is to investigate the accuracy parameter generators to produce input data for commonly used concrete material models. The second objective is to establish and evaluate a simplified parameter calibration procedure based on standard material experiments and data from the literature. The results employing parameter generators varied notably between the models while still giving decent ballpark estimates. The parameters obtained from inverse modelling of standardized material tests improved the results significantly. The findings of this study recommend caution when using automatic parameter generators. Although a detailed calibration of these concrete models is complicated, a simplified calibration gives reasonable predictions, making this the advisable approach for designing concrete protective structures.

Dynamic response of honeycomb cored sandwich panels under high velocity impact: A numerical study

To investigate the impact resisting behavior of honeycomb cored sandwich panel under the bullet attacks, birds and debris, computational analysis of ballistic impact tests have been performed. The honeycomb sandwich panel with SS 316L front and back sheets are used owing to its better impact resistance, high ductility and superior strength for impact resisting applications. The Ballistic test simulations under a wide range of 150 to 800 m/s have been carried out on a SS 316L sandwich panel embedded with Aluminum alloy (AA 3003) honeycomb core using ABAQUS/Explicit software. For this, 12 mm thick sandwich panel and three types of bullet profiles namely conical, hemispherical and blunt are considered. The initial and residual velocity obtained from the simulation is used for computing the dynamic energy absorption of the panels. The significance of projectile velocity, nose shape on overall energy absorption capacity of the panel have been thoroughly investigated. The sandwich panel reportedly absorbed 20.6% and 41.2% higher energy when impacted with blunt projectile than those impacted with hemispherical and conical bullets. Moreover, an almost linear increase in the overall energy absorption capacity of the panel have been observed by increasing the striking sheet thickness.

Extreme Anisotropic Dispersion and One-Dimensional Confined Electrons in 2-D SiP₂ FETs With High Transmission Coefficients

2-D semiconductors are promising Si alternatives for channels in next-generation electronic devices. Considering the 2-D SiP2 with unique dispersion at the band edge and intrinsic P–P chains with 1-D confined electrons, we provide a comprehensive investigation on the electronic and ballistic transport properties of SiP2. Based on first-principle and ballistic quantum transport simulations, the 2-D SiP2 exhibits a strong anisotropy in both geometric structures and electronic properties, playing a critical role in the anisotropy of transmission path and device performance for SiP2 field-effect transistors (FETs). Considering the ultrahigh saturation current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {sat}}$ </tex-math></inline-formula> ) of SiP2 FETs in along-chain direction, the transfer characteristic with different gate lengths (3–12 nm) is calculated to thoroughly evaluate the performance. As a result, 5–12 nm SiP2 n-FETs with underlap (UL) configuration can fulfill the International Technology Roadmap for Semiconductors (ITRS) and International Roadmap for Devices and Systems (IRDS) goals, showing an ultrahigh ON-state current of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3420 ~{\mu } \text{A}/ {\mu } \text{m}$ </tex-math></inline-formula> with 10 nm gate length. In addition, the figures of merits, such as delay time and power dissipation, are comprehensively assessed, proving the fast-switching and low-energy consumption ability of SiP2 FETs. Hence, our study demonstrates the great potential of 2-D SiP2 for future competitive electronic devices.

Efficient two-dimension particle element method of interior ballistic two-phase flow

Reducing the calculation cost is of great importance as the demand for interior ballistic calculation is increasing. The key factor of interior ballistic simulation is the quest to develop a more efficient method. In this paper, an efficient two-dimension particle element method (PEM) is proposed to simulate the detailed multidimensional flow of the gas and propellant particle in the chamber. Firstly, several real particles are packed as the particle element to reduce the calculation of the solid phase. In particular, the particle element matrix is established to describe the distribution of particle parameters. Secondly, the particle element boundary is adjusted according to the particle’s movement to reduce the computational cost of grid generation. Besides, the dynamic self-adapting mesh map method is adopted to realise the coupling computation between gas phase and the particle element. The application of a standard virtual gun as a standard benchmark for interior ballistic codes is used to validate the accuracy and reliability with 1.68% error. The particle element model accurately describes the distribution of flow field in the chamber. Compared with the two-fluid method, the PEM significantly improves the computational efficiency by 21.7%. The PEM may be promising for the rapid simulation of two-phase flow in interior ballistic.

Prediction of Tail-Off Pressure Peak Anomaly on Small-Scale Rocket Motors

Numerical studies intended to predict solid rocket motors anomalies are the major contributors when developing strategies to both limit expensive fire tests and to investigate and understand the physical phenomena from which anomalies can arise. This paper aims to present a mathematical–physical method to evaluate the pressure peak, namely Friedman Curl, occurring at the tail-off phase of small-scale rocket motors. Such phenomenon is linked to the grain solid particles arrangement (i.e., packing effect); indeed, those particles show a tendency to accumulate at a certain distance from the metallic case, implying a local burn rate increment and a combustion chamber pressure rise close to the tail-off phase. Comparisons between experimental and simulated combustion chamber pressure profiles are outlined to prove the effectiveness of the mathematical–physical approach. Simulations were carried out with an internal ballistic simulation tool developed by the authors of this work.

Experimental and numerical study on failure mechanisms of bone simulants subjected to projectile impact.

Analyses of the human bones failure mechanisms under projectile impact conditions can be made through performing of a large number of ballistic trials. But the amount of data that can be collected during ballistic experiments is limited due to the high dynamics of the process and its destructive character. Numerical analyses may support experimental methodologies allowing to better understand the principles of the phenomenon. Therefore, the main aim of the study was to create and to verify a numerical model of commercially available synthetic bone material-Synbone®. The model could be used in the future as a supporting tool facilitating forensic studies or designing processes of personal protection systems (helmets, bulletproof vests, etc.). Although Synbone® is commonly used in the ballistic experiments, the literature lacks reliable numerical models of this material. In order to define a numerical model of Synbone®, mechanical experiments characterizing the response of the material to the applied loads in a wide range of strains and strain rates were carried out. Based on the mechanical tests results, an appropriate material model was selected for the Synbone® composite and the values of constants in its equations were determined. Material characterization experiments were subsequently reproduced with numerical simulations and a high correlation of the results was obtained. The final validation of the material model was based on the comparison of the ballistic impact experiments and simulation results. High similarity obtained (relative error lower than 10%) demonstrates that the numerical model of Synbone® material was properly defined.

Ballistic Penetration Test and Simulation of Metallic Aircraft Wing Fuel Tank

Ballistic Penetration Test and Simulation of Metallic Aircraft Wing Fuel Tank

ВПЛИВ ТЕМПЕРАТУРИ ІМІТАТОРА ЦІЛІ З БАЛІСТИЧНОГО ПЛАСТИЛІНУ НА РЕЗУЛЬТАТИ ДІЇ ЕЛЕМЕНТА, ЩО ВРАЖАЄ

Due to the complexity of modeling terminal ballistics processes and the necessity to apply numerous assumptions, the investigation of the impact of the projectile's energy characteristics on the target is best conducted using experimental methods. Ballistic plasticine, especially the "Beschussmasse" brand, is widely used for simulating processes associated with firearm injuries. A challenge with any target simulator is the temperature dependence of its mechanical properties. Decreased temperatures lead to increased strength and reduced plasticity of materials and vice versa. It has been established that the volume and shape of the cavity depend not only on the target simulator's temperature but also on the kinetic energy of the impacting element. The research has yielded empirical relationships between the volume of the final cavity in the ballistic plasticine target simulator and the temperature of the target simulator and the kinetic energy of the impacting element. These relationships allow for the assessment of the impact of the striking element on the target simulator, specifically on the volume of the final cavity within the temperature range of the plasticine target simulator from 5°C to 25°C. Results obtained at any given temperature of the target simulator can be adjusted to the volume of the final cavity at normal temperature. This eliminates the need to strictly adhere to the normal temperature of the target simulator, significantly simplifying the process of related experimental research. To reduce the relative error in measuring the volume of the final cavity, it is advisable to prefer higher temperatures of the target simulator (within the investigated range). The direction of further research involves establishing the relationship between the effects of the impacting element with identical characteristics on a biological target and a target simulator, followed by correlating the damages of the target simulator to the biological target.

Internal Ballistic Modeling and Simulation Analysis of High-low Pressure Low-overload Launch of Unmanned Aircraft

The low-overload launch is an important research direction in weapon launch. In this paper, a new low-overload launch method is designed by using the piston-type high-low pressure launch principle combined with the secondary launch principle. Based on the classical internal ballistic equations and multi-body dynamics equations, the internal ballistic model of this low overload launch system is established. A joint simulation model based on MATLAB and RecurDyn is constructed to simulate the internal ballistic state during the launch process. The sensitivity of each parameter change of the high-low pressure system to the launch overload is also studied. The results show that the maximum low-pressure chamber pressure of the low overload launcher in this paper is reduced by 62% compared to the conventional internal ballistic pressure, the saturation of the pressure curve is also improved, and the muzzle velocity is accelerated; the maximum overload is reduced by 65%, which can meet the requirements of muzzle initial velocity and low overload when launching unmanned aircraft.

Dynamic pressure-based rocket PID parameters adaptive adjustment method and application

This paper establishes a dynamic pressure-based PID parameter adjustment method, which uses the function of the ratio of the maximum dynamic pressure of the rocket to the actual dynamic pressure of the current flight to correct the rocket control parameters. Compared with the traditional time-based PID parameter gain scheduling method, the number of PID parameters to be adjusted is significantly reduced from nearly 50 to 10, and the adjustment complexity is significantly reduced. Based on the method in this paper, the PID parameter debugging of the attitude control of a model-guided rocket is completed. The six-degree-of-freedom ballistic simulation results show that the control law obtained by the method in this paper meets the requirements of the attitude control of the model-guided rocket, and is superior to the traditional time-based PID parameter gain adjustment method in terms of response rate.