• Title/Summary/Keyword: figured-porous

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A Discussion on the Radiation Efficiency Measurement of Porous Surface Flames (다공성 표면 화염의 복사열효율측정에 관한 논의)

  • Jeong, Hwanghui;Sim, Keunseon;Lee, Keeman
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.157-159
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    • 2014
  • This article describes an investigation of basic combustion characteristics of radiant burner with various firing rate and equivalence ratios in porous metal. As a main experimental condition, firing rates and equivalence ratios each were adjusted from 204 to $408kW/m^2$ and 0.6 to 1.3. The purpose of this study is to investigate radiation efficiency using two experiment methods. The first way is to calculate the radiation efficiency by measuring the temperature of the burner surface, and the second is to compute the radiation efficiency by measuring the radiation intensity of the burner surface with a radio meter. The value of the radiation efficiency did not exactly match in the two cases. But we figured out that in accordance with increasing heat power, radiation efficiency was decreased. And additional complementary experiment on the relationship between these values is needed.

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Numerical simulation of thermo-fluid flow in the blast furnace (고로내 열유동 현상의 수치해석 사례(I))

  • Jin, Hong-jong;Choi, Sang-Min
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2038-2043
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    • 2007
  • Analysis of the internal state of the blast furnace is needed to predict and control the operating condition. Especially, it is important to develop modeling of blast furnace for predicting cohesive zone because shape of cohesive zone influences on overall operating condition of blast furnace such as gas flow, temperature distribution and chemical reactions. Because many previous blast furnace models assumed cohesive zone to be fixed, they can't evaluate change of cohesive zone shape by operation condition such as PCR, blast condition and production rate. In this study, an axi-symmetric 2-dimensional steady state model is proposed to simulate blast furnace process using the general purpose-simulation code. And Porous media is assumed for the gas flow and the potential flow for the solid flow. Velocity, pressure and temperature distribution for gas and solid are displayed as the simulation results. The cohesive zones are figured in 3 different operating conditions.

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Fundamental Study of Domestic Wood for the Materials for High-class Furnitures and Woodcrafts -Anatomical & Physical Characteristics of Chestnut Woods Grown in Korea- (국산목재의 고급가구 및 목공예 용재 개발을 위한 기초연구 - 국내산 밤나무 7품종의 해부 및 물리적 특성-)

  • Lee, Seon-Hwa;Kwon, Sung-Min;Park, Byung-Ho;Lee, Sung-Jae;Lee, Uk;Kim, Mahn-Jo;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.6
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    • pp.23-32
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    • 2008
  • Anatomical and physical characteristics of seven cultivars of chestnut wood (Castanea crenata Sieb. et Zucc.), Tanzawa, Ibuki, Mansung, Arima, Ginyose, Tsukuba, and Riheiguri, were investigated to obtain some valuable information for their possibilities to be used for high quality furnitures and woodcrafts. Solitary pore and figured-porous or ring-porous wood types were observed in wide growth rings, and ring-porous in narrow growth rings. Procumbent type was prevalent in ray cells although upright and square types were scarcely existed. Uniseriate, biseriate, and multiseriate rays were observed in tangential section. Uniseriate ray was abundant near the pith, and biseriate and multiseriate rays were frequently existed near the bark. The occurrence rate of biseriate and multiseriate rays was significantly high in Tanzawa, Ibuki, Mansung and Tsukuba, but was somewhat low in Arima, Ginyose and Riheiguri. The inner region showed larger vessel diameter, more vessel number, fewer ray number and higher ray height than the outer region. Growth-ring width in inner region was larger than that in outer region. Growth-rings in inner region of Mansung and Arima were wide while that of Ibuki was narrow. Outer region in all cultivars showed higher latewood percentage than inner region. Especially, Mansung and Tsukuba showed significantly high latewood percentage in their outer region. Green moisture content and density of heartwood were higher than those of sapwood. Tsukuba and Riheiguri had higher green moisture content, and Ibuki and Riheiguri had higher green density than the other chestnut cultivars.