• 한국군사과학기술학회지
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• 제13권3호
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• pp.349-357
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• 2010

In this paper, a numerical code for the interior ballistics has been investigated. The Eulerian-Lagrangian approach and the SMART scheme have been used in the numerical code for the grain combustion. The translational kinetic energy of the projectile and work done against barrel friction have been considered only. The ghost cell extrapolation method has been used for the chamber change with the projectile movement. The calculation results of the numerical code have been compared and verified through those of IBHVG2 code.

• 한국군사과학기술학회지
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• 제15권3호
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• pp.241-249
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• 2012

Performance analysis of the interior ballistics has been conducted using the 1-D numerical code called IBcode according to the various conditions such as length of ignition-gas injector, amount of ignition-gas, mass of projectile, and drag force of projectile. In case of the length of ignition-gas injector, the 25~100 % of the full-injector length has been considered as well as the mass & mass flow of the ignition-gas. The mass of the projectile 5~70 kg and its drag force of 0~69 MPa have been also considered. Variables such as breech & base pressure, negative differential pressure and muzzle velocity for the performance analysis have been sorted, too. Firing conditions for the optimal performance have been investigated through these variables.

• 한국군사과학기술학회지
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• 제14권1호
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• pp.22-29
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• 2011

Using the numerical code for the interior ballistics, the performance of the interior ballistics with the characteristic of the ignition-gas injections has been investigated. The ignition gas has been assumed to be injected into the chamber with 3 cases. As the results of analysis, when the ignition-gas has been injected into all chamber area, the pressure distributions of the chamber of the interior ballistics have been uniform and the differential pressure has been stable. The ignition-gas has been injected into the partial area of the chamber, however, the pressure distributions and the differential pressure have been unstable. The case using the longer ignition injector, therefore, seems to be more suitable to improve the stability of the interior ballistics.

• 한국군사과학기술학회지
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• 제25권3호
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• pp.321-328
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• 2022

The current development tend of the gun propellants that they should have low sensitivity and high energy. We studied a nitrocellulose based propellant composition that replaced sensitive NG with RDX and DEGDN which high energy and low sensitivity. The important factors in the design of the gun propellant were impetus and flame temperature. NC-based propellant containing RDX showed similar impetus but low flame temperature compared to KM30A1, a triple-based propellant. The developed propellant composition didn't show any abnormal combustion reaction and the characteristics of ballistic resistance were also confirmed.

• 한국군사과학기술학회지
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• 제27권3호
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• pp.428-435
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• 2024

The important factors in the design of the gun propellant are impetus, flame temperature and pressure. In this paper, we considered a nitrocellulose based propellant composition that replaced sensitive NG(Nitroglycerin) with RDX(Cyclotrimethylenetrinitramine) and DEGDN(Diethylene glycol dinitrate) which high energy and low sensitivity. Particle size and content of RDX are the two main factors that affect the burning stability of RDX-based propellants. Among them, the characteristics of the propellant according to the particle size of RDX were confirmed. The relative combustion rate(R.Q., Relative Quickness) of the propellant changed according to the RDX particle size, and internal ballistics of properties of propellant were also varied. The particle size of RDX can be confirmed as a major factor in the combustion and internal ballistics characteristics of the propellant.

• 한국항공우주학회지
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• 제41권10호
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• pp.796-804
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• 2013

연소 및 추진 기관 공학 교육 과정의 일부로써 간단한 형태의 열기관인 감자총 (Potato Gun)의 제작, 시험 및 해석을 수행하였다. 정적 연소실의 화학 평형 해석을 이용하여 연소실의 압력을 계산하고, 팽창과정의 열역학 해석을 통하여 열에너지의 운동에너지로 변환되는 내탄도 과정을 계산하였다. 공기역학적 지식을 도입한 구형 탄도 궤적 해석을 통하여 비행거리를 추정할 수 있었으며, 이를 통하여 감자총의 에너지 변환 효율 및 혼합기의 당량비를 추정하였다. 본 과제는 재활용 자재를 이용하여 학부 수준에서 열-유체역학공학 지식을 활용하여 실습하고 학생들의 관심을 유발할 수 있는 적당한 예로 여겨진다.

• 한국군사과학기술학회지
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• 제7권2호
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• pp.5-12
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• 2004

The erosion wear of gun barrel occurs due to heat and chemical reactions. The high pressure and temperature in chamber increase the erosion wear. It is known that the metal phase transfer is the primary wear factor in a gun barrel under high temperature. In this paper, the tool of wear prediction in high pressure gun tube has been developed. The program developed has three modules such as DIRECT(interior ballistics analysis module), INVERSE(gun design module), and WEAR(wear prediction module). The prediction of wear was compared with the experimental data which was collected in the field unit. The prediction results shows good trend with the collected data.

• 한국군사과학기술학회지
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• 제22권1호
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• pp.27-34
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• 2019

This paper presents a chamber pressure model development of K2 rifle by applying Gaussian mixture model. In order to materialize a real recoil force of a virtual reality shooting rifle in military combat training, the chamber pressure which is one of major components of the recoil force needs to be investigated and modeled. Over 200,000 data of the chamber pressure were collected by implementing live fire experiments with both K100 and M193 of 5.56 mm bullets. Gaussian mixture method was also applied to create a mathematical model that satisfies nonlinear, asymmetry, and deviations of the chamber pressure which is caused by irregular characteristics of propellant combustion. In addition, Polynomial and Fourier Regression were used for comparison of results, and the sum of squared errors, the coefficient of determination and root-mean-square errors were analyzed for performance measurement.

• 한국군사과학기술학회지
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• 제20권4호
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• pp.514-519
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• 2017

To develop a gun propellant composition with high insensitivity and high energy, we formulated a composition by adding RDX into the nitrocellulose(NC) based propellant. The flame temperature of the RDX added NC(RAN) propellant was higher than that of neat NC propellant. The kinetic muzzle energy of RAN propellant was close to that of JA2 propellant at room temperature($21^{\circ}C$). The difference of kinetic muzzle energy of RAN propellant between high and room temperature settings as well as between a low and room temperature settings were less compared to those of JA2 propellant.

• 한국군사과학기술학회지
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• 제26권5호
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• pp.371-383
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• 2023

Artillery gun tube experiences very high pressure according to the blast of propellant charge. Therfore, it is essential to guarantee the structural safety of the gun tube. On the other hand, weight reduction of gun tube is also a crucial design factor since the agility of artillery vehicle directly leads to its survivability. In this line of thought, this work proposed an efficient design procedure which utilizes the convex combination of breech pressure and projectile base pressure time histories. Its efficiency is verified by comparing with other procedures. Other procedures utilize different computed max pressure rather than the convex combination design pressure. Additionally, a transient analysis is carried out considering the projectile movement and the corresponding pressure distribution through the newly developed ABAQUS user-subroutine. The analysis confirms the structural safety of the lightweight gun tube designed by the proposed method.