• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.2
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• pp.18-25
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• 2017

The study for the combustion characteristics of propellants for nozzleless boosters was carried out. The metal fuels of Al and Zr were introduced into solid propellant formulations in order to enhance the density-specific impulse and the high burning rate with low pressure exponent was investigated as the major combustion characteristic of propellant to design nozzleless boosters. The burning rate of Zr-containing propellant was higher than Al-containing propellant and, $13{\mu}m$ Zr-containing propellant exhibited the burning rate of 35 mm/s (at 1000 psi)and pressure exponent of 0.3282. The benefit of using Al and Zr-containing propellant into nozzleless boosters was demonstrated in these results.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.39-45
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• 2013

Basically, in order to apply solid propellant as ignition source to high energy metal particle combustion system, we analyzed combustion characteristics of the HTPB/AP/Al, HTPE/AP/Al propellants by using a strand burner. The propellants were tested in a high-pressure windowed strand burner, which was pressurized up to 300 psia with pure argon gas. Strand burner was visualized with two quartz windows and ignition was accomplished by a 10 W $CO_2$ laser. The burning rate of propellant was measured with high-speed camera method for frame analysis and photodiode method for combustion time analysis. Emission spectrum was measured with spectrometer at 300 nm ~ 800 nm and 1500 nm ~ 5000 nm and then we analyzed species during propellant combustion.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.1081-1086
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• 1994

The phenomena called "combustion instabilities" in a solid-propellant rocket motor may be viewed as sustaining or amplifying pressure waves. Energy is supplied by combustion processes near the surface of the burning propellant. T-burner method is used to determine the response function of the propellant to the pressure wave. But initial tests were failed because of the Helmholtz resonation inside the T-burner. Acoustic analysis of the original T-burner is carried out and suppression techniques for the Helmholtz oscillation are introduced.ntroduced.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.2
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• pp.21-26
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• 2019

Exposure to a rapidly depressurized environment causes extinction of a burning solid propellant. Experiments have been conducted to determine the rate of depressurization required to extinguish a burning solid propellant. For this purpose, a depressurization combustor was designed and fabricated. The results of this experiment were used to determine the boundary between extinction and non-extinction of AP/HTPB solid propellants under different propellant compositions. Experimental results show that the initial and final pressures have a considerable effect on the critical depressurization rate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.972-977
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• 2017

The propellant tile and crack which account for the greatest proportion of solid rockets are profoundly affected by viscosity and mechanical properties of solid propellant. In this paper solid propellant with nitrate ester polyester(NEPE) system has been researched for the viscosity, mechanical properties and burning properties with size and mixing ratio of RDX. the viscosity of propellant was changed significantly depending on the size of RDX and mixing ratio, and mechanical properties of NEPE system propellant were also varied. Considering both lower viscosity and stable mechanical properties, the optimum size and mixing ratio of RDX can be identified as the main factors to the NEPE system propellant.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.3
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• pp.9-17
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• 2002

This Study is to investigate 8 composite propellants including Butacene and ${Bi_2}{O_3}$ by Shotgun/RQ Bomb test. Burning rate and mechanical properity are known to be major factors in determining the deflagrability of propellant. Propellant including over 5.5% Butacene(Ferrocene grafted HTPB) burned out over 135 m/s of impact velocity during Shotgun/RQ Bomb test. It was blown that Butacene was very sensitive material under high velocity impact. In the test results, propellants under 25mm/s in burning rate at 1500 psia could meet the requirements for IM of UN Test Series 7c(ii). Propellant deflagrabillity depends on burning rate at performance in the results of the present.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.38-47
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• 2013

Traditional propellants release toxic gases during combustion that are harmful to the environment. This study describes a novel synthetic process of two high nitrogen containing tetrazines, TATTz and BTATz, which can be adapted as solid fuels for a solution to environmental concerns. The compounds were characterized by NMR, IR spectroscopy, and differential scanning calorimetry(DSC). Detonation properties were calculated with the EXPLO5 program based on calculated heats of formation and measured densities.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.356-359
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• 2011

In this study, applicable to Sounding Rocket about the development of high-performance propellant was studied. Sounding Rocket requires generally multistage rocket system for atmospheric research. This study describes the development of two types solid propellant compositions which are based on HTPB/AP for the two-stage rocket. CEA code of NASA and internal ballistic analysis were used for confirming the theoretical performance of designed propellants. The strand burner and JANNAF tensile test was used to measure ballistic and mechanical properties of designed propellants. Finally, static fired test of standard motors was performed to prove the possibility of development.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.4
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• pp.16-24
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• 2013

The analysis of performance and internal flow according to various numerical models for interior ballistics has been conducted. The initial flow has been mainly affected by the drag model of propellants and their drag degradation reduces oscillations of differential pressure between the breech and the shot base. Models of Nusselt number haven't influenced the major performance of interior ballistics. The negative differential pressure isn't generated in the case without the heat transfer of propellants.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.6
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• pp.1-8
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• 2007

The objective of the present work is to characterize design parameters of solid propellant ignitor for composite, double base, and nitramine propellants using arc image furnace. Arc image furnace and fiber optics surface reflectometer were used to measure ignition delay time and reflected optical energy of several compositions of composite, double base and nitramine base rocket propellant at different pressure levels each other. The order of ignitability was double base > composite> nitramine propellants at initial pressure of over 75 psia. The highest ignition energy was needed to ignite nitramine propellant, however, the ignition delay time decreased abruptly as the pressure increased up to the range of $75{\sim}400$ psia. The absorbtion of radiation energy could be increased by the addition of small amount of opacifiers as carbon black, ZrC, WC and burning catalyst.