• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.957-967
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• 2017

Firing test of the fuel grain for solid fuel ramjet with additives and ignition support material was conducted. Fuel grain consist of HTPB mixed with AP particle 15 wt.%, Boron particle 5 wt.%. To cause the short ignition delay, ignition support consist of $NC/BKNO_3$ and composite propellant was coated to the fuel grain. An oxidant gas having a controlled temperature, pressure and oxygen composition close to the air condition in the ramjet combustor was supplied using the Ethanol blended $H_2O_2$ gas generator. Gas was set to flow at a mass flow rate of 150 g/s and mass flux of $200kg/m^2s$ in the grain port. Through the test, ignition support operated well and ignition delay of 0.5. During the test, stable chamber pressure with 8 bar and high combustion efficiency of 0.86 was confirmed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.555-558
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• 2010

This paper presents a design of solid rocket motor with high length to diameter applied composite propellant. Solid rocket motor with high L/D ratio can be generated erosive burning and combustion instability on longitudinal mode. Especially, Erosive burning can effectively prolong the initial pressure spike in some star grain motors. That is, the study shows design of grain, internal ballistics and structural analysis in order to perform system requirements.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.4
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• pp.21-27
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• 2022

In this paper, the combustion characteristics of solid propellant embedded with metal wires were analyzed by the ground tests of motors. The propellant grains were made of thermoplastic propellants with Al and Cu as metal wires for the enhancement of burning area and designed with cone shape for better ignition. These metals were used to confirm the enhancement of burning rate on thermal diffusivity properties. The internal ballistics analysis and ground test were performed to investigate the effect of burning rate for each metal wire. We obtained the results of burning rate on a difference of thermal diffusivity of each metal wire with well-made propellant grains.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.3
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• pp.69-76
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• 2012

An achieving method of highly progressive pressure gradient is presented to enhance the missile ejection system's performance by using a gas generator in the condition of preventing erosive burning. To obtain and confirm a stable burning, a ground burning test was performed to evaluate the new methods of a radial-hole and a multi-row propellant grain. The test results show that a radial-hole grain takes good effect on erosive burning and not on ejection performance. On the other hand, a multi-row grain which reduces the length-to-diameter ratio(L/D) of grain is very effective to prevent the erosive burning and to enhance the ejection performance simultaneously.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.432-439
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• 2011

An achieving method of highly progressive pressure gradient is presented to enhance the missile ejection system's performance by using a gas generator in the condition of preventing erosive burning. To obtain and confirm a stable burning, a ground burning test was performed to evaluate the new methods of a radial-hole and a multi-row propellant grain. The test results show that a radial-hole grain takes good effect on erosive burning and not on ejection performance. On the other hand, a multi-row grain which reduces the legnth-to-diameter ratio(L/D) of grain is very effective to prevent the erosive burning and to enhance the ejection performance simultaneously.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.6
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• pp.91-97
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• 2015

The limit values of mechanical properties(MPs) of HTPB/AP/Al Solid Propellant was reviewed according to the rocket motor development procedures and the in-process values of MPs were analyzed by the tool of Process Capability Index. Based on finding the dependency among MPs, the optimization is proposed for reducing the properties defects and for improving the rocket grain safeties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.286-290
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• 2008

This paper summarizes the components of an explicit aeroelastic solver developed especially for the simulation of dynamic fracture events occurring during the flight of solid propellant rockets. The numerical method combines an explicit Arbitrary Lagrangian Eulerian (ALE) version of the Cohesive Volumetric Finite Element (CVFE) scheme, used to simulate the spontaneous motion of one or more cracks propagating dynamically through a domain with regressing boundaries, and an explicit unstructured finite volume Euler code to follow the flow field during the failure event. A key feature of the algorithm is the ability to adaptively repair and expand the fluid mesh to handle the large geometrical changes associated with grain deformation and crack motion.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.45-52
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• 2020

In this paper, a subminiature solid rocket motor(SSRM) was designed to develop a miniature smart-bullet and the designed propellant grain was made of thermoplastic propellant for production convenience of inner shape. The internal ballistics analysis and ground test were performed to investigate the performance of SSRM. And a numerical simulation was carried out to obtain basic data on the design of safety distance between the nozzle outlet and a gunner, the temperature distribution of exhaust gas was analyzed by comparing a numerical simulation and the results of IR camera.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.1
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• pp.35-41
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• 2019

Ferrocene and ferrocene derivatives have been widely used as a burning rate catalyst for composite solid propellants. However, its tendency to migrate through the propellant grain and to crystallize at the surface changes the composition of propellant which results in unpredictable burning rate. To overcome the weakness of ferrocene catalyst, we designed a polymer containing ferrocene, poly(glycidyl azide-co-glycidyl ferrocenyl ether) (GAFP). GAFPs were synthesized from poly(epichlorohydrin-co-glycidyl ferrocenyl ether) (PEGF) which has ferrocenyl ethers in its pendant groups. The structures of GAFPs were confirmed by FT-IR, $^1H$ and $^{13}C$ NMR spectral analyses. Thermal properties of the GAFPs were evaluated using differential scanning calorimeter (DSC). As the contents of ferrocene increased, the glass transition temperature ($T_g$) of the GAFPs shifted to a higher temperature, and the decomposition temperature ($T_d$) decreased because the ferrocene worked as a burning rate catalyst.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.207-210
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• 2007

This paper describes the development of the grain design automation program using commercial CAD(computer-aided-design) software. This program allows to readily obtain output of burning area, volume, moments of inertial, motion of the center of gravity, and other geometric data as a function of regressed distance. These are utilized in performance analysis.