• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.664-667
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• 2010

Solid rocket propulsion systems are generally used for tactical missiles due to the structural and operational simplicity. Nevertheless, various kinds of design factors including outer diameter, length, weight, loading efficiency of propellant grain effects to thrust performance. Dual thrust is beneficial to range extension and terminal velocity increasement. But loading efficiency becomes low in case to obtain dual thrust performance by burning surface control. So, It is predicted to be reasonable to obtain dual thrust performance with high/low burning rate propellants. This study is on internal ballistic analysis and ground test to confirm dual thrust performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.9
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• pp.25-32
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• 2006

In this study, the characteristics of filament wound composite/aluminum ring specimens were investigated at cryogenic temperature. The ring specimens were manufactured using carbon fibre and Type B epoxy resin which had been developed for cryogenic use. As a result of measuring thermal strains at -150℃, it was found that compressive thermal stress was induced in composite part on the contrary, tensile thermal stress in aluminum part which was about 32% of yield stress and in turn, caused aluminum to be yielded at lower load level. In addition, Thermal strains which resulted from finite element analysis showed good agreement with those of the experiment. After 6 mechanical loading cycles had been applied to the ring specimen at -150℃, tensile tests were performed at -150℃ using a split disk fixture. As a result, it was shown that composite strength in a liner-composite tank structure which is for the use of cryogenic propellant tank would be decreased by auto-frettage pressure which is applied to it.

• Membrane Journal
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• v.22 no.4
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• pp.235-242
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• 2012

Ammonium perchlorate (AP) is primarily derived from the process of liquid incineration treatment when dismantling a solid rocket propellant. A series of batch dead-end nanofiltration (NF) and reverse osmosis (RO) membrane experiments were conducted to explore the retention mechanisms of AP under various hydrodynamic and solution conditions. Low levels of silicate type of siloxane had been detected through the GC/MS and FTIR analysis of liquid solutions extracted from solid ammonium perchlorate composite propellant (APCP). It is indicated that NF/RO membranes fouling in the presence of APCP was mainly attributed to the AP interactions because the concentration of silicate type of siloxane was negligible compared to that of AP. The osmotic pressure of AP was presumably resulted in the flux declines ranging from 13 to 17% in the case of the application of low-pressure (551 and 896 kPa for NF and RO) compared to those in application of high-pressure. The retention of AP by NF/RO membranes significantly varied from approximately 10 to 70% for NF and 26 to 87% for RO, depending on the operating and solution water chemistry conditions. The results suggested that retention efficiency of AP was fairly increased by reducing concentration polarization (i.e. application of low-pressure and stirring speed of 600 rpm) and increasing the pH of a solution. The result of this study was also consistent with the previous modeling of 'solute mass transfer of NF/RO membranes' and demonstrated that hydrodynamic and solution water chemistry conditions are to be a key factor in the retention of AP by NF/RO membranes.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.29-34
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• 2014

Particulate reinforced composite is composed of hard particles and polymer matrix. This material has been widely applied for engineering industry such as automobile, construction and aerospace. For the safe application, it is important to assess crack resistance behavior. Especially in aerospace industry, crack could cause significant problem when the material is used for solid rocket fuel. Therefore, it is inevitable to estimate the characteristics of the crack propagation. In this study, crack propagation tests were conducted using particulate reinforced composite under crosshead rate 2.54 mm/min in the range of temperature $-60^{\circ}C$ to $60^{\circ}C$. The strain contour of surface for specimen was generated using digital image correlation method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.16-19
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• 2005

The basic research on KM(Kick Motor) for space launch vehicle was carried out. KM whick will be used as 2nd stage solid rocket motor. in Korean Satellite Launch Vehicle(I) has been developing. KM is a solid rocket motor using composite propellant based on HTPB and is composed of composite motor case and submerged nozzle. To develop KM rocket motor satisfing a given set of requirement, firstly the full-scale KM was designed, then sub-scale motor reduced about $50\%$ were manufactured and tested.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.834-841
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• 2010

The STSAT-3 (science and technology satellite) is the first satellite whose entire structure was made of composite materials in Korea and it will be launched later in 2011. As like other small satellites, it is also equipped with several advanced instruments whose major objectives focused on the scientific tests in space. The HPS (hall thruster propulsion system) using xenon gas as a propellant has been developed and its overall ground tests were conducted. This research emphasizes on the technologies and procedure applied to the development of the entire HPS and its function and environment tests.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.886-898
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• 2008

A survey is offered of the present status of microaluminized propellants industrially used worldwide in most space applications, but new directions are also pointed out making profitable use of the nanoaluminized propellants currently tested in many laboratories. Different industrial- and research-type of solid rocket propellants, mainly but not only, of the well-known family oxidizer/Al/HTPB(oxidizer being AP, AN or a mixture of the two) were experimentally analyzed at the Space Propulsion Laboratory of Politecnico di Milano. In general, they feature the same nominal composition but implement different grain size distributions of the oxidizer or metal fuel. The basic properties of all formulations were compared to that of a standard propellant already certified for flight.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.1-8
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• 2015

Dual pulse rocket motor is a variant of solid rocket motor with two propellant grain separated by a pulse separation device. The major performance of such a rocket motor is influenced by the change in the hole area of pulse separation device to nozzle throat area ratio. In this study, we performed flow analysis to investigate the internal flow characteristics according to the pulse separation device hole area to nozzle throat area ratio change. Gases used flow analysis were used combustion gas of HTPB/AP composite propellant and nitrogen gas. Flow analysis results of the dual pulse rocket motor were validated by comparison with experimental results of pneumatics. Commercial CFD code ANSYS FLUENT 14.5 is used in this study to simulate flow analysis.

• Composites Research
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• v.19 no.4
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• pp.23-30
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• 2006

In the development of a cryogenic propellant tank, the proper selection of adhesives to bond composite and metal liner is important for the safety of operation. In this study, 3 types of adhesives were tested for the ability to bond CFRP composites developed for cryogenic use and aluminum alloy (Al 6061-T6) for lining the tank using double-lap joint specimens. The double-lap joint specimens were tested inside an environmental chamber at room temperature and cryogenic temperature ($-150^{\circ}C$) respectively to compare the bond strength of each adhesive and fracture characteristics. The material properties with temperature of component materials of double-lap joints were measured. In addition, ABAQUS was used for the purpose of analyzing the experimental results.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.1
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• pp.95-103
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• 1999

Low pressure combustion characteristics of the composite solid propellants were studied in terms of the propellant burning rate, ignition processes, and the structure of the extinguished surfaces. Optical Vacuum Strand Burner(OVSB) system was designed and configured for this purpose. Burning rates of the propellants were measured at subatmospheric pressure by developed test method in OVSB. The ignition and combustion phenomena of the studied propellants in the combustion chamber of OVSB were recorded and analyzed with the camera and VCR(30 frames/s). Burning surfaces of the propellants were extinguished by rapid depressurization method and analyzed with Scanning Electron Microscope(SEM).