• Title/Summary/Keyword: Cubical Cavity

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Numerical Study on Natural Convectionin a Doubly-Inclined Cubical-Cavity (이중으로 경사진 3차원 캐비티내 자연대류 열전달현상에 관한 수치해석적 연구)

  • Myong, Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.12
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    • pp.1002-1008
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    • 2007
  • Natural convection flows in a doubly-inclined cubical air-filled cavity are numerically simulated by a solution code(PowerCFD) using unstructured cell-centered method. For a physical realizability, the cavity has one pair of opposing isothermal faces at different temperatures, $T_h\;and\;T_c$, respectively, the remaining four faces having a linear variation from $T_c\;to\;T_h$. The paper redefines a new doubly-inclined orientation for the cubical-cavity benchmark problem. Special attention is paid to three-dimensional thermal characteristics in natural convection according to the new orientation at $Ra=4\times10^4$. Comparisons of the average Nusselt number at the cold face are made with benchmark solutions and experimental results found in the literature. It is found that the average Nusselt number at the cold face has a maximum value at the doubly-inclined angle ranging from $40^{\circ}\;to\; 45^{\circ}$ We also report the effect of new orientation on the type of temperature structure in a doubly-inclined cubical-cavity.

Numerical Study on Slanted Cubical-Cavity Natural Convection (경사진 3차원 캐비티내 자연대류현상에 관한 수치적 연구)

  • Myong, Hyon-Kook;Kim, Jong-Eun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.9
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    • pp.722-728
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    • 2006
  • Natural convection flows in a cubical air-filled slanted cavity that has one pair of opposing faces isothermal at different temperatures, $T_h\;and\;T_c$, respectively, the remaining four faces having a linear variation from $T_c\;toT_h$ are numerically simulated by a solution code (PowerCFD) using unstructured cell-centered method. Special attention is paid to three-dimensional flow and thermal characteristics according to a new orientation (diamond type) for the cubical-cavity benchmark problem in natural convection. Comparisons of the average Nusselt number at the cold face are made with experimental benchmark solutions found in the literature. It is found that the code is capable of producing accurately the nature of the laminar convection in a cubical air-filled slanted cavity with differentially heated walls.

NUMERICAL SIMULATION OF NATURAL CONVECTION IN A CUBICAL-CAVITY BY UNSTRUCTURED CELL-CENTERED METHOD (비정렬 셀 중심 방법에 의한 3차원 캐비티내의 자연대류 현상에 관한 수치해석)

  • Myong H. K.;Kim J. E.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.61-66
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    • 2005
  • Natural convection flows in a cubical, air-filled cavity that has one pair of opposing faces isothermal at different temperatures, Th and Tc, the remaining faces having a linear variation from Tc to Th are numerically simulated by a new solution code(PowerCFD) using unstructured cell-centered method. Solutions are obtained for configurations with a Rayleigh number as high as 105 and three inclination angles ${\theta}$ of the isothermal faces from horizontal: namely ${\theta}=0$, 45 and $90^{\circ}$. Interesting features are presented in detail and comparisons are made with benchmark solutions and experimental results found in the literature. It is found that the code is capable of producing accurately the nature of the laminar convection in a cubical, air-filled cavity with differentially heated walls.

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NUMERICAL STUDY ON NATURAL CONVECTION IN A CUBICAL-CAVITY WITH A DIAMOND-TYPE ORIENTATION : Ra = $1{\times}10^5$ (다이아몬드형태의 3차원 캐비티내 자연대류 유동에 관한 수치적 연구 : Ra = $1{\times}105$)

  • Kim, J.E.;Myong, H.K.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.83-88
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    • 2006
  • Natural convection flows in a cubical air-filled cavity that has one pair of opposing faces isothermal at different temperatures, $T_h\;and\;T_c$ respectively, the remaining four faces having a linear variation from $T_c\;to\;T_h$ are numerically simulated by a solution code(PowerCFD) using unstructured cell-centered method. An extension to a previously published work, special attention of this work is paid to three-dimensional flow and thermal characteristics in nature convection according to new orientation at Ra= $1{\times}105$. Comparisons of the average Nusselt number at the cold face are made with benchmark solutions and experimental results found in the literature. It is demonstrated that the average Nusselt number on the cold face has a maximum value around the diamond-type inclination angle of $43.2^{\circ}\;at\;Ra=1{\times}105$. We also report the effect of new orientation on the type of flow and temperature structure in a cubical-cavity.

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Numerical Study on the Characteristics of Natural Convection Flows in a Cubical Cavity (3차원 정육면체 캐비티내 자연대류 유동 특성에 관한 수치해석적 연구)

  • Myong Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.4 s.247
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    • pp.337-342
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    • 2006
  • Natural convection flows in a cubical air-filled cavity that has one pair of opposing faces isothermal at different temperatures, $T_h\;and\;T_c$, respectively, the remaining four faces having a linear variation from $T_c\;to\;T_h$ are numerically simulated by a solution code(PowerCFD) using unstructured cell-centered method. Special attention is paid to three-dimensional flow and thermal characteristics according to the variation of inclination angle $\theta$ of the isothermal faces from horizontal: namely $\theta=0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;50^{\circ},\;60^{\circ},\;75^{\circ}\;and\;90^{\circ}$. Comparisons of the average Nusselt number at the cold face are made with experimental benchmark results found in the literature. It is demonstrated that the average Nusselt number at the cold face has a maximum value around the inclination angle of $50^{\circ}$. It is also found that the code is capable of producing accurately the nature of the laminar convection in a cubical air-filled cavity with differentially heated walls.

Numerical Investigation on Heat Transfer Characteristics for Natural Convection Flows in a Doubly-Inclined Cubical-Cavity (이중으로 경사진 3차원 캐비티내 자연대류 열전달 특성에 관한 수치해석적 연구)

  • Myong, Hyon-Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.6
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    • pp.435-442
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    • 2009
  • Three-dimensional heat transfer characteristics for natural convection flows are numerically investigated in the doubly-inclined cubical-cavity according to the variation of a newly defined orientation angle �� of the hot wall surface from horizontal plane at moderate Rayleigh numbers. Numerical simulations of laminar flows are conducted in the range of Rayleigh numbers($10^4{\leq}Ra{\leq}10^5$) and $0^{\circ}{\leq}{\alpha}90^{circ}$ with a solution code(PowerCFD) employing unstructured cell-centered method. Comparisons of the average Nusselt number at the cold face are made with benchmark solutions and experimental results found in the literature. It is found that the average Nusselt number at the cold wall has a maximum value around the specified orientation ${\alpha}$ at each Rayleigh number. Special attention is also paid to three-dimensional thermal characteristics in natural convection according to new orientation angles at Ra��= $1{\times}10^5$, in order to investigate a new additional heat transfer characteristic found in the range of above Ra = $6{\times}10^4$.