• Journal of the Korea Society for Simulation
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• v.20 no.2
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• pp.41-48
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• 2011

Naval Gun FCS(Fire Control System) is the most fundamental weapon system in Naval Combat System. Simulationbased verification of FCS is mandatory before sea trial since ballistic solution needs complicated process and uses almost all information produced by own ship sensors. The FCS simulation method is proposed for verification of naval gun FCS and applicable to the FCS design depending on combat system development phase based on available data in each design phase. Verified FCS through proposed simulation method is adapted in real naval combat system and the performance has been proven by sea trial.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.778-780
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• 2017

In order to calculate the performance of the solid rocket motor, the internal ballistics analysis code using HLLC scheme has been developed. The result of applying the analysis code to the actual motor shape has been compared with the experimental results and it is confirmed that the performance of the solid rocket motor has been well calculated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.97-100
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• 2008

A hybrid sounding rocket carrying about 10kg payload reaching up to 15km altitude has been designed. The commercial seamless aluminium tube and liquid ${N_2}O$ without pressurization devices were chosen as rocket motor case and oxidizer supply system respectively. A hybrid rocket engine performing required propulsion impulse is designed with time dependent internal ballistic scheme. Engine performance, aerodynamic characteristics, and trajectory were predicted by a integral technique of internal ballistics and external ballistics. The design results were evaluated by comparison with previous experimental data, technical reports, and literatures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.148-151
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• 2010

심장관련 질환은 현대사회에서 업무 과중과 스트레스에 의해 발병 가능성이 높아지고 있으며, 일상생활 중 건강상태를 지속적으로 모니터링하여 심장질환 관련 응급상황에 대처하기위한 많은 연구들이 수행되고 있다. 본 연구에서는 가정 또는 사무실에서 무구속적인 방법으로 지속적인 심장 활동상태의 모니터링이 가능한 무구속 의자형 심탄도 계측 시스템을 구현하였다. 구현된 시스템에서 계측된 심탄도 신호로부터 건강모니터링을 위한 특징성분을 검출하기위해 웨이브렛 변환과 템플릿 매칭을 혼합한 신호처리방법을 제안하였다. 또한 적응 문턱치를 통해 심탄도 신호에서 심박동을 검출하였으며 심박동의 간격으로부터 HRV(heart rate variabillity)를 계산하였다. 구현된 시스템의 성능평가를 위하여 심전도와 동시에 심탄도를 측정하였으며, 두 신호로부터 심박동 검출 성능을 비교하여 구현된 무구속 의자형 심탄도 계측 시스템의 유용성 및 무자각 건강모니터링의 가능성을 확인하였다. 또한 스트레스에 따른 HRV의 변화를 관찰하기 위하여 피실험자로부터 인위적으로 숨을 참고 강제호기를 통해 흉강내압을 증가시켜 인위적인 육체적 스트레스를 가하는 발살바를 유도하였으며, HRV의 시간 및 주파수 영역에서 도출되는 파라미터들을 평가하여 심탄도 모니터링을 통해 안정 상태와 스트레스 상태의 판별 및 무구속 건강모니터링의 가능성을 평가하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.40-47
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• 2014

The grain burn-back analysis has been performed for the internal ballistics analysis code to be used for the optimal design of the space launch vehicles. The grain burn-back has been used to calculate the burning surface that is essential to the internal ballistics. The calculation of internal ballistics code used in the optimal design is repeated until satisfying the required performance through the change of the design parameter. Therefore, the burn-back method applied to the internal ballistics analysis should be easy to change the design parameter and calculation time should be short. In this study, a burn-back analysis code has been developed using the analysis method. Also, geometric parameters of the grain have been selected and organized. The developed code has been verified by comparison of results of a numerical method.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.3
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• pp.61-67
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• 2017

In this study, Burning Area Analysis Program (BAAP) was developed by using VOF method to estimate the burning area of 3D shaped grain. The parametric study of mesh size, burning rate and time interval for numerical calculation was conducted. The result of BAAP is compared with the one from commercial 3D modeling software. Also the internal ballistic analysis was performed using the result of BAAP. In order to estimate the burning area and internal pressure with time, Chemical Equilibrium Analysis (CEA) was conducted with a composition of reduced smoke propellant. As a result, the web-averaged pressure was 5.34 MPa which is similar to the published research result.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.6
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• pp.12-20
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• 2008

The efficient plan and numerical methods for development of the interior ballistics code have been investigated. The schemes of the numerical code for the moving boundary with the projectile movement have been compared and verified through the free piston motion problem. The combustion of solid propellants and the pressure gradient in the chamber by the porosity effect have been predicted based on the numerical calculation of the initial combustion of the interior ballistics. Computerization techniques of the fundamental schemes and plans for development of the numerical analysis code for the interior ballistics have been obtained.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.215-218
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• 2007

Internal Ballistic modeling and performance prediction for solid propellant micro thruster was performed with heat loss to the chamber wall as an important factor of miniaturization. Simple l-D end-burner type thruster and general HTPB-AP type composite propellant were selected for computation model. The results showed that the performance loss with the heat loss to the surroundings becomes larger as the surface-to-volume ratio is increased. In this case, the total impulse was reduced about 3% of the case in adiabatic condition.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.1-8
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• 1991

The geoid is the one of major suject in Geophysics and Geodesy. The iregularities of the geoid will affect the computation of precise geodetic coordinates and moreover will cause an errors in trajectory computations and reference directions for inertial guidance system. The aim of this study is to develope the best local geoid model for Korea. For this purpose, an astrogeodetic levelling and surface fitting techniques have been applied in determination of the geoid as a first trials. As a result of it, a local geoid has been obtained with the standard errors of $\pm$0.49m and $\pm$0.66m respectively and the maximum geoid undulation in Korea is found as 22m~23m approximately.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.3
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• pp.187-194
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• 2015

Course correction munition is a smart projectile which improves its accuracy by the control mechanism equipped in the fuze section with canard. In this paper, various aerodynamic configurations of the fuze section were analysed by utilizing a semi-empirical method and a CFD method. A final canard configuration showing the least drag was then determined. During the CFD simulation, it was found that the k-${\omega}$ SST turbulence model combined with O-type grid base is suitable for the prediction of the base drag. Finally, the aerodynamic characteristics of the smart munition and the change of drag due to the canard installation were analysed.