• Title/Summary/Keyword: Bum-sin

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Flame Propagation Characteristics in a Heavy Duty Liquid Phase LPG Injection SI Engine by Flame Visualization (대형 액상 LPG 분사식 SI 엔진에서 화염 가시화를 이용한 희박영역에서의 화염 전파특성 연구)

  • 김승규;배충식;이승목;김창업;강건용
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.4
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    • pp.23-32
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    • 2002
  • Combustion and flame propagation characteristics of the liquid phase LPG injection (LPLI) engine were investigated in a single cylinder optical engine. Lean bum operation is needed to reduce thermal stress of exhaust manifold and engine knock in a heavy duty LPG engine. An LPLI system has advantages on lean operation. Optimized engine design parameters such as swirl, injection timing and piston geometry can improve lean bum performance with LPLI system. In this study, the effects of piston geometry along with injection timing and swirl ratio on flame propagation characteristics were investigated. A series of bottom-view flame images were taken from direct visualization using an W intensified high-speed CCD camera. Concepts of flame area speed, In addition to flame propagation patterns and thermodynamic heat release analysis, was introduced to analyze the flame propagation characteristics. The results show the correlation between the flame propagation characteristics, which is related to engine performance of lean region, and engine design parameters such as swirl ratio, piston geometry and injection timing. Stronger swirl resulted in foster flame propagation under open valve injection. The flame speed was significantly affected by injection timing under open valve injection conditions; supposedly due to the charge stratification. Piston geometry affected flame propagation through squish effects.

A Study on the Model Development of CHP optimal operation algorithm (열병합발전소의 최적운전 알고리즘 개발)

  • Kim, Yong-Ha;Back, Bum-Min;Woo, Sung-Min;Lee, Kwang-Seong;Sin, Hyeong-Cheol
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.522-523
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    • 2008
  • This paper develops optimal operation mechanism of CHP(Combine Heat and Power) for enhancement of energy efficiency. It verify optimal operation of Accumulator using Economic Heat Load Dispatch and Dynamic Programing through case study.

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Stiffness-Based Optimization for the Lateral Drift Control of Outrigger System (아웃리거시스템의 횡변위제어를 위한 강성최적화 기법)

  • Lee, Han-Joo;Park, Young-Sin;Nam, Kyung-Yun;Lee, Seong-Su;Shin, Hyo-Bum;Kim, Ho-Soo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.210-215
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    • 2008
  • This study presents an effective stiffness-based optimal technique to control quantitatively lateral drift and evaluates the structural behavior characteristics and efficiency for tall outrigger system subject to lateral loads. To this end, displacement sensitivity depending on behavior characteristics of outrigger system is established and approximation concept that can efficiently solve large scale problems is introduced. Specifically, under the 'constant-shape' assumption, resizing technique of member is developed. Two types of 60 story frameworks are presented to illustrate the features of the quantitative lateral drift control technique proposed in this study.

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Numerical Prediction of Turbulent Heat Transfer to Low Prandtl Bumber fluid Flow through Rod Bundles

  • Chung, Bum-Jin;Kim, Sin
    • Journal of Energy Engineering
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    • v.7 no.2
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    • pp.187-193
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    • 1998
  • The turbulent heat transfer to low Prandtl number fluid flow through rod bundles is analyzed using k-$\varepsilon$ two-equation model. For the prediction of the turbulent flow field, an anisotropic eddy viscosity model is used. In the analysis of the temperature field, the effects of various parameters such as geometry, Reynolds and Prandtl numbers are considered. The calculation in made for Prandtl numbers from 0.001 to 0.1 in order to analyze the heat transfer to low Prandtl number fluid such as liquid metals. The numerical results show that for small P/D (Pitch/Diameter) geometries low Prandtl number makes severe changes of the rod surface temperature.

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