• Title/Summary/Keyword: muffler heat

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Study on the Simulation of the 4-Stroke Cycle Spark Ignition Engines (First Paper) (4 행정 사이클 스파크 점화기관의 시뮬레이션에 관한 연구 (제1보))

  • 윤건식;우석근;서문진;신승한
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.6
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    • pp.1260-1271
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    • 2001
  • The simulation program which predicts the gas behavior in a spark ignition engine has been developed and verified by the comparison with the experimental results foy the MPI engine, naturally aspirated and turbochared engines with a carburettor. First paper describes the calculations of the behavior of gas in the intake and exhaust system. The generalized method of characteristics including friction, heat transfer, area change and entropy gradients was used to analyse the pipe flow The constant-Pressure model was applied for the analysis of the flow through engine valved, and the constant-pressure perfect-mixing model was applied for the flow at manifold junction. The concept of the sudden area change was used for the muffler and catalytic convertor. Fer the plenum chamber in an MPI engine, constant-pressure model and constant-volume model were both examined. Through the comparison of predicted results with experiments, the simulation program was verified by showing good prediction of the behavior of IC engine qualitatively and quantitatively under wide range of operating conditions.

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Research on the Actual Conditions of the Onmapsi Campaign and Its Satisfaction of Government Officers (공무원의 온맵시 의복 착용과 캠페인 만족도 조사)

  • Na, Young-Joo;Son, Min-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.9
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    • pp.991-999
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    • 2012
  • The Korean wintertime Onmapsi Campaign recommends wearing underwear, layered clothing, or thermal accessories in an indoor environment of a lower than room-heating condition. We surveyed 132 government officers, about Onmapsi wearing conditions and campaign satisfaction. The term was found to be unfamiliar to them, even if they wore underwear or thermal accessories as participants in the campaign for the wintertime office of low temperature 18-$20^{\circ}C$. They wore thick shirt/pants or cardigans/sweaters; however, underwear or thermal vests was worn relatively less. They wear 2.9 layers on top and 1.7 layers in bottom in average. They have their own methods to keep the body warm, which are using 1) functional thermal clothing, such as turtleneck shirts of heat technology new material, 2) functional thermal accessories, such as warmer and muffler, 3) functional office goods, such as a thermal computer mouse and blanket on the desk. The campaign requires more advertisement, a revision on the details of the proper wintertime indoor environment, and develops the varieties of Onmapsi apparel.

A Study for Fire Examples Involved with Absorbing Material Breakaway and Electric Short in Engine Room of a Large Bus (대형 버스의 엔진룸에서 흡음재이탈 및 전기적인 단락에 관련된 화재 사례 고찰)

  • Lee, IL Kwon;Kook, Chang Ho;Ham, Sung Hoon;Lee, Young Suk;Hwang, Han Sub;You, Chang Bae;Moon, Hak Hoon;Lee, Jeong Ho
    • Journal of the Korean Institute of Gas
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    • v.24 no.2
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    • pp.9-14
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    • 2020
  • This paper is a purpose to study the failure examples for a large bus vehicle fire. The first example, the researcher certified the fact that the absorbing material break away from the upper side of engine room because of weaken durability and the fire was produced in engine. The second example, it sought the fact that the fire breaks out by electric short because of over-load of compressor. The third example, it found the fact that the fire took place by heating of bellows upper part that was connected with muffler and exhaust manifold. The fourth example, it knew the fact that the fire occurred because of the electric short inside junction box of crash body part that was located to driver seat rightside. Therefore, the fire of a large bus occurring by decrepit of absorbing material and electric short have to thoroughgoingly manage the damage and dangerousness if it happens.