• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.223-227
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• 2006

In this study, the combustion characteristics was studied with various oxidizer in hybrid propulsion system. In this experiments $GN_2O$ and GOX were used as oxidizer, and PE was used as fuel. The combustion behavior was explained by flame temperature with mass O/F ratio, and the use of $GN_2O$ as the oxidizer caused a increase in combustion efficiency with GOX in the same hybrid motor. The mass flow rate of gaseous oxidizer was controlled by the several chocked orifices that have different diameter, and the oxidizer supply range was $0.0138{\sim}0.0427kg/sec$. As result, the empirical relation for oxidizer type was represented by mass flux of solid fuel, it was obtained with mass transfer number, and mass flux of oxidizer.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.203-207
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• 2007

In this study, the combustion characteristics of HTPB was studied in hybrid propulsion system. In this experiments HTPB was used as fuel, GOX was used as oxidizer. The mass flow rate of GOX was controlled by the several chocked orifices that have different diameter, and the oxidizer supply range was $13.8{\sim}42.7g/sec$. The experimental result of HTPB was compared with the other studies of HTPB, and the combustion performance of HTPB was analyzed with that of PE. As a result, the homing rate and efficiency of HTPB as fuel were better than that of PE in the same hybrid motor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.797-802
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• 2017

This paper describes the scale effect of hybrid rocket motor which has blow-down oxidizer supply system. ResuIts show that the scale effect on regression rate is negligible using presently accessible scaling relation for $LN_2O$/PE propellant combination amid the absence of exactly proven scaling relation. It was also found that the characteristic velocity efficiency increases as motor scale increases. However, the characteristic velocity efficiency includes complicated parameters such as post-chamber configuration or geometry which can affect the entire flow field. It is therefore hard to conclude that the increase of efficiency is solely due to the enlargement of motor scale nor draw any conclusion on the scale effect which require a profound understanding of hybrid rocket scaling rules.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.55-62
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• 2011

In this study, we tried to improve the thrust control performance through the thrust control combustion experiment of the hybrid rocket. We constructed the system which controls the oxidizer flow by combining a needle valve with a stepping motor and controlling the stepping motor drive according to the thrust control command order. Gas oxygen was used as the oxidizer for two different propellants, PE(Polyethylene), PC(Polycarbonate), respectively. To improve the slow response time and the oscillation phenomenon in the beginning stage of the thrust control combustion experiment, we measured and analyzed the change of the flow speed of the propellant pipe. The revised thrust control combustion experiment showed that the thrust was stably controlled with the margin or error from the thrust command within ${\pm}1$ N.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.6
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• pp.53-59
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• 2021

The ROK Navy operates many war ships despite its short history. Various types of war ships, such as submarines, destroyers, frigates, corvette etc., use suitable propulsion systems for the operational requirements of each war ship. A hybrid propulsion system was introduced to change from the current mechanical propulsion system to an electric propulsion system according to the changing patterns of naval warfare, and it is expected that an integrated electric propulsion system will also be introduced. Therefore, this paper investigates the propulsion system of major ships operated by the Korean Navy, predicts the changes in future naval warfare, and proposes a propulsion system for future ships.

• Bulletin of the Korea Photovoltaic Society
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• v.2 no.1
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• pp.26-35
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• 2016

• KIPE Magazine
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• v.26 no.5
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• pp.53-59
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• 2021

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.188-191
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• 2009

제3차 신재생에너지 기본 계획에서는 기존의 태양광10만호 보급사업을 확대하여 모든 가능한 신재생에너지 부존자원을 최대한 활용하는 통합형 보급 사업으로서의 "2020 그린홈(Green Home) 100만호 사업"이 새로이 추진 중에 있다. 이 사업의 핵심 내용으로는 수요자중심의 맞춤형 주택공급과 이로 인한 민간시장의 활성화, 그리고 하이브리드형 신재생 에너지 시스템 개발 등을 꼽을 수 있다. 본 연구는 지난 "1-2차 신재생 에너지 기술개발 및 이용 보급 기본 계획"에서 추진된 주택용 신 재생에너지 보급 정책 결과와 일본, 독일 등의 해외사례 연구를 바탕으로 현재 시행중인 제 3차 기본계획 추진 과정을 검토하여 다음과 같은 제언을 하고 있다. 즉, 향후 신재생에너지 주택보급 사업의 원활한 수행을 위해서는 치밀한 준비를 통해 사업을 내실있게 추진해야 하고, 계획된 예산을 안정적으로 확보하고 효율적으로 배분하여 사업에 대한 신뢰성을 확보해야 한다. 또한 합리적인 목표 설정을 통해 체계적인 보급 정책을 추진해야 하고, 기술개발과 보급 양 부문에 대한 적절한 균형을 도모해야 한다.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.21-29
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• 2002

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. The recent research efforts are focused on the improvement of volume limitation and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the eddy breakup model and Hiroyasu and Nagle and Strickland-Constable model are used for soot formation and soot oxidation. Radiative heat transfer is modeled by finite volume method. To reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect, the Low Reynolds number $\kappa-\varepsilon$ turbulent model is employed. Based on numerical results, the detailed discussion has been made for the turbulent combustion processes in the vortex hybrid rocket engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.112-118
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• 2019

The development of an underwater rocket propulsion system was described in this paper. Throttle able liquid propellant and hybrid rocket propulsion systems were selected for underwater propulsion. A subscale liquid rocket combustion chamber and it's portable stand were developed and their applicability was examined. 1.5-ton.f and 1.8-ton.f hybrid rockets were developed for underwater applications. The test results indicated that the 18-ton.f hybrid rocket fully complies to the performance and underwater cruise stability requirements; thus, its development was concluded to be successfully complete.