• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.58-66
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• 2019

In this study, the start-up characteristics of a staged combustion engine were analyzed numerically based on relational equation modeling of the entire engine components. The start-up characteristics were extensively analyzed considering the transient period of the total engine system from the start-up sequence till the steady-state of the engine. The performance characteristics of the engine components such as RPM of engine power-pack, chamber pressure and O/F ratio of pre-burner, and mass flow of propellants in the start-up period were investigated. Furthermore, the calculated engine data were compared satisfactorily with the experimental data. Through the comparison of data, successful validation of present engine start-up analysis has been obtained.

• Defense and Technology
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• no.10 s.164
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• pp.43-44
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• 1992

복합재 연소관과 노즐을 기계적 체결방법으로 결합하면 결합부위에서 재료의 불연속성과 기하학적 불연속성으로 인한 높은 응력집중이 발생해 구조적으로 매우 취약하게 됩니다. 복합재 연소관의 경우에는 내압을 받는 원통형 구조물이므로 기존의 평판에 대한 연구결과를 그대로 사용할수 없으므로, 이 글에서는 복합재 셀 구조물의 응력 및 파손 해석을 수행할수 있도록 1차전단변형 셀이론을 이용한 유한요소해석 프로그램을 개발하였습니다. 기계적체결부위의 모델링에 대해 검토하였으며 복합재료의 파손평가에 사용되는 여러가지 파손식을 적용해 비교하였습니다. 이 해석 방법을 이용해 복합재 연소관의 적층각, 볼트직경, 연소관의 끝단까지의 길이 등이 파손하중에 미치는 영향을 제시하였습니다

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1997.10a
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• pp.93-98
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• 1997

도시폐기물의 효율적인 소각 처리를 위해서 폐기물 처리량 50 ton/day의 화격자 소각로를 대상으로 화학반응을 고려하여 연소실 내부의 열유동 현상을 전산모사하였다. 수치해석 프로그램으로 상용코드인 PHOENICS를 사용하여 3차원 모사를 하여 실험으로 파악할 수 없는 연소실 내부의 유동 및 폐기물과 산화제와의 반응을 계산하였다. 건조부, 주연소부, 후연소부에 1차연소용공기, 연료의 분포 및 폐기물의 발열량이 노내 열유동 현상에 미치는 영향을 조사하였다. 1차연소용 공기의 분포에 따라 노내 유동장의 형태에 변화가 있었으며, 벽면에서의 복사열전달을 고려한 경우 2차연소실과 출구근처에서 온도분포가 파일롯트 플랜트 실험결과와 잘 일치하는 r서으로 나타났다.

• Journal of the Korean Society of Combustion
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• v.18 no.3
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• pp.61-67
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• 2013

This study introduces the design methods for air flow distribution at the level of preliminary design, and reviews the typical combustion process and main functions of sub-components of aircraft gas turbine combustors. There are lots of design approaches and empirical equations introduced for air flow distributions at the combustors. It is shown that a decision on which design approaches work for the combustor development is totally dependent upon the objective of engine design, target performance, and so on. The current results suggested for preliminary air flow distributions need to be validated by combustor geometry checkups and performance evaluations for future works.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1744-1759
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• 1992

A multidimensional simulation of turbulent flow and combustion with swirl in the cylinder of SI engine is implemented to clarify the effects of swirl. present simulation employs the ICED-ALE numerical technique, the skew-upwind difference scheme, a modified k_.epsilon. turbulence model, a combustion model of Arrhenius type and turbulence-mixing-control type. First, the calculations for swirling flow in an axisymmetric cylinder are carried out. The results are compared with the experimental data to validate the numerical analysis. Second, the calculations for intake, compression and combustion processes in an axisymmetric cylinder are performed. The effects of swirl on turbulent flow and combustion are examined through the parametric study of swirl number 0.0, 0.6, 1.2 and 2.4. As a result, it is numerically shown that the turbulent kinetic energy and the swirl velocity, which are produced during the intake process, affect the combustion process.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.278-281
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• 2004

The purpose of this paper is to show a reliable analytical method to predict the deflections of F/W Composite Motor Case. Structural analysis and testing of a Carbon/Epoxy Composites Motor Case for Pressure Loadings were performed. This paper presents the development of 3-D layered axi-symmetric solid element for finite element analysis. Finite element analyses were preformed considering fiber angle variation in longitudinal and thickness direction by ANSYS. The analytical results agree well with experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.46-51
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• 2012

This study aims to develop the performance analysis program on the staged combustion cycle of the liquid rocket engine using liquid oxygen(LOx) as oxidizer, liquid hydrogen(LH2) and RP-1 as fuel. The developed analysis program can obtain the propellant mass flow rate, the specific impulse, and representative design values of engine components for the required thrust satisfying pressure, mass flow, and energy balance conditions. The analysis results show that the the specific impulses (Isp) compared to those of the real engines have been less than 1%. With additional constraints, the program will be improved for the system optimization.

• Nuclear Engineering and Technology
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• v.11 no.4
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• pp.275-286
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• 1979

In 600 MWe CANDU-PHW reactors PMCR will be used on-site for calibration of the regional overpower system. PMCR will be executed off-line in one of the station computers. The program calculates accurate channel power maps by incorporating a fuel turnup dependent flux to power conversion algorithm. Fuel turnup is calculated by PMCR, hence it is independent of other software. Extensive comparisons with the uniform flux/power conversion approximations were made. Significant improvements in power mapping accuracy are achieved with PMCR.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.122-130
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• 2016

This study is a numerical study using commercial simulation program GT-Power on 1.5MW diesel engine for power generation. Performance comparison has done for diesel operation with dual fuel operation for different engine load(50%, 75%, 100%) using the target engine model with additional gas injection system. Effect of using Hi-sene, which is actually being used in island area, instead of diesel was also studied. As a result, under 60% natural gas with diesel condition, BSFC was increased by 32% without modifying system. There was almost no change for natural gas/Hi-sene condition compared with natural gas/diesel condition. Decrease of burned fuel fraction was the main reason of these phenomena. After optimizing system, BSFC was improved by 2%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.2
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• pp.103-109
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• 2013

In this study, we performed a numerical study of hydrogen/air combustion in the combustion chamber of an ultra micro gas turbine. The supply flow rate and equivalence ratio are used as variables, and the commercial computational fluid dynamic program (STAR-CCM) is used for the numerical study of the combustion. The flow rate significantly affects the flame position, flame temperature, and pressure ratio between the inlet and the outlet. The flame position is close to the outlet in the combustion chamber, and the flame temperature and pressure ratio monotonously increases with the supply flow rate. The change in the equivalence ratio does not affect the flame position. The maximum flame temperature occurs under stoichiometric conditions.