• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.60-60
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• 2002

비행탄의 종말속도증대를 위하여 고체램제트를 이용하는 개념은 현재 세계적으로 여러나라에서 연구 중에 있다. Solid Fuel Ramjet Propulsion(고체연료 렘제트 추진)은 로켓추진에 비하여 월등히 높은 비추력을 가지며 구조적으로 매우 간단하여 탄의 사거리 및 평균속도를 증대시키는 좋은 수단으로 사용되고 있다. 그러나 간단한 구조에도 불구하고 고체렘제트의 작동은 매우 다양한 물리적 현상이 연관되므로 필요한 성능을 얻기 위해서는 이들의 상호 작용을 고려하여 설계의 최적화 및 성능 예측이 필요하다.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.1
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• pp.12-19
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• 2022

The propellants used in the gas generator of the ducted rocket are fuel-rich propellants, which contain an excessive amount of metal fuel and a small amount of oxidizing agent compared to general solid rocket propellants. In this paper, boron powder and MgAl(Magnesium-Aluminium alloy) were applied to produce fuel-rich propellants. The optimum formulation was determined by characterizing these metal fuel-rich propellants. Analysis of combustion products in the gas generators confirmed that the fuel-rich propellants containing fine boron powder itself instead of boron-bead could be useful in gas generators.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.4
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• pp.44-53
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• 2022

The depressurization rate in a thrust variable solid rocket motor is the major factor that has the greatest influence on the thrust termination performance. In this study, the depressurization rates range of model solid rocket motor was identified and major factors affecting the depressurization rate were found. It is important for actual system design to understand the depressurization rate of the system that can satisfy the target performance as well as the extinguishing characteristics of the solid propellant. The methodology for obtaining the depressurization rate model in this study is considered to be applicable to the optimal design of the thrust terminable propulsion system.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.6
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• pp.28-33
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• 2022

In this study, the curing characteristics of commonly used Hydroxyl terminated polybutadiene(HTPB)-based solid propellant according to the curing temperature and Equivalent ratio change were investigated. In addition, the effect of curing reaction according to their ratio and content in the Triphenyl bismuth(TPB), Maleic anhydride(MA) and Magnesium oxide(MgO) catalyst systems was confirmed. Finally, moisture was added for each propellant mixing process to check the effect of moisture on propellant curing.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.283-292
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• 2008

The foremost criterion in the design of a Satellite Launch Vehicle(SLV) is its performance capability to boost the designated payload to the desired mission orbit; it starts from focusing on the SLV configuration to achieve the velocity requirements($}\Delta}V$) for the mission. In this paper we review an analytical approach which is suitable enough for preliminary conceptual design and is used previously to optimize stage configurations for Two Stage to Orbit SLV for Low Earth Orbit(LEO) Missions; we have extended this approach to Three Stage to Orbit SLV and compared different propellant options for the mission. The objective is to minimize the Gross Lift off Weight(GLOW). The primary performance figures of merit were the total inert weight of the SLV and the payload weight that the SLV could lift into LEO, given candidate propulsion systems. The optimization is achieved by configuring the $}\Delta}V$ between stages. A comparison of configurations of single-stage and multi-stage SLVs is made for different propellants. Based upon the optimized stage configurations a comparative performance analysis is made between Liquid and Solid fueled SLV. A 3 degree of freedom trajectory-analysis program is modeled in SIMULINK and used to conduct the performance analysis. Furthermore, a cost analysis is performed on our stage optimized SLVs. The cost estimation relationships(CER) used give us a comparison of development and fabrication costs for the Liquid vs. Solid fueled SLV in man years. The pros and cons of the production, operation ability, performance, responsiveness, logistics, price, shelf life, storage etc of both Solid and Liquid fueled SLVs are discussed. The statistics and data are used from existing or historical(real) SLV stages.

• 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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.149-152
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• 2012

This paper describes the study of integrated hydrogen supply system for environment friendly propulsion systems of fuel-cell UAV. Diluted hydrochloric acid was used for direct-decomposing solid-state $NaBH_4$ and generating hydrogen. Self-hydrogen pressurized reactor and pressure regulator was introduced for stable hydrogen supply. Prototype of integrated hydrogen supply systems using the solid-state $NaBH_4$ direct-decomposition was designed for performance evaluation and concept demonstration.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.383-387
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• 2011

The supercavitating rocket torpedo SHKVAL was analyzed in view of its system operation procedure and the structure and performance. 3 different propulsion systems installed in SHKVAL were 1st solid rocket booster for launch and acceleration, 2nd solid rocket booster for further acceleration, and Mg-rich Hydroreactive fuel rocket propulsion system for cruising. The gas generator used to help generate the supercavitation bubble was composed of a solid propellant gas generator and a hydroreactive fuel one. The structures and their performance were described based on as much knowledge as we have obtained from cumulative information and up-to-date analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.942-948
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• 2011

Solid propulsion systems have simple structures compared to other propulsion systems and are suitable for long-term storage. However the systems generally have limits on control of thrust levels. In this paper we introduce controllers for combustion chamber pressure using on-off control techniques which have been known for relatively easy implementation and energy efficiency. For this, we use a simple pressure change model by considering only mass conservation within the combustion chamber and we design a classical controllers and on-off controllers with are Pulse Width Modulation(PWM) and Pulse Width Pulse Frequency Modulation (PWPFM). Then we compare the performance results of the controllers through numerical simulations.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.4
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• pp.77-84
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• 2006

With the development of micro/nano spacecraft, concepts of micro propulsion are introduced for orbit transfer and drag compensation as well as attitude control. Micro solid propellant thruster has been attention as one of possible solution for micro thruster. In this paper, micro solid propellant thruster is introduced and research on basic components of a micro solid propellant thruster is reported. Micro Pt igniter was fabricated through negative patterning and quantitative effect of geometry was estimated. The characteristic of HTPB/AP solid propellant was investigated to measure the homing velocity. A combustion chamber was fabricated by means of anisotropic etching of photosensitive glass. Finally, micro solid propellant thrusters having various geometries were fabricated and tested.