• 제목/요약/키워드: 공간 복사열유속 분포

검색결과 3건 처리시간 0.015초

Characteristics of Heat Flux in a Compartment Fire - Reduced Scale Test (구획공간 화재의 열유속 특성 - 축소 실험)

  • Kim, Sung-Chan;Ko, Gwon-Hyun
    • Fire Science and Engineering
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    • 제25권5호
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    • pp.128-133
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    • 2011
  • The present study performs a series of 40 % reduced scale of ISO-9705 fire test to investigate the characteristics of heat flux on the floor level in terms of fire characteristics and location in the compartment. The heat flux was measured with Schmidt-Boelter type heat flux gauge at two locations on the floor level of inside and doorway side of the compartment. Different types of fuel - methane, heptane, toluene, ethanol, polystyrene - were burned in this test series. The measured heat flux inside of the compartment was relatively higher than that of front side as the heat release rate of fire and upper layer temperature increased. The difference of measured heat flux at inside and doorway side increased for high sooty fire. The present study shows that the heat flux distribution at lower layer greatly depend on the thermal radiation from fire and upper layer, not only the upper layer temperature but also various fire characteristics such as composition of combustion gases, soot concentration, ventilation condition and so on.

Numerical simulations of radiative and convective heat transfer in the cylinder of a diesel engine (디이젤엔진내의 복사열전달 효과에 관한 수치해석적 연구)

  • 임승욱;김동우;이준식
    • Journal of the korean Society of Automotive Engineers
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    • 제14권2호
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    • pp.54-64
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    • 1992
  • During combustion process in a diesel engine radiation heat transfer is the same order of magnitude as the convection heat transfer. An approximation of heat and momentum source distributions is applied at a level consistent with those used in modelling the soot distribution and the turbulence instead of modelling the fuel spray and the chemical kinetics. This paper illustrates a use of the third order spherical harmonics approximation to the radiative transfer equation and delta-Eddington approximation to the scattering phase function for droplets in the flow. Results are obtained numerically by a time marching finite difference scheme. This study aims to compare heat transfer with convection heat transfer and to investigate the importance of scattering by fuel droplets and of accounting for spatial variations in the extinction coefficient on the radiative heat flux distributions at the walls of a disc shaped diesel engine.

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The Effects of Winch-curtain Ventilation on the Indoor Environment of a Fattening Swine House (윈치커튼 환기가 비육돈사의 실내 환경에 미치는 영향)

  • Kim, Hyeon-Tae;Song, Jun-Ik;Choi, Hong-Lim
    • Journal of Animal Environmental Science
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    • 제18권1호
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    • pp.1-8
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    • 2012
  • The study was conducted to investigate the effects of climate on indoor environment of a swine house with natural. This study was tested in the beef swine stall at Young-in, Kyung-ki do. The test was experimented for the effect of interior environment by the outdoor environment and the interior-pan. The results are as follows. 1. In test 1 ($T_{out}$ : $25.7^{\circ}C$, without fan), an indoor air flow pattern was showed that entered from sidewall winch-curtain to went out of a indoor by the ridge winch-curtain. And the velocity of a section of the center was measured two times as large as the velocity of the floor. It is the acceleration of the velocity by thermal buoyancy. And, the entered air was rapidly dissipated by flow energy. So that in the swain livestock with sidewall winch-curtain is effected by thermal buoyancy. And the air temperature of the indoor was distributed more higher as compared with the outdoor temperature. This result is caused by the sensible heat from swine and the ventilation is restricted. 2. In test 2 (($T_{out}$ : $25.7^{\circ}C$, with fan), the velocity of a section of the center was measured more higher as compared with the test 1. And the variance of air velocity was distributed higher as compared with the test 1. This result is showed dead region of air flow with a fan operation. And, the variance of gas density was distributed lower as compared with the test 1.