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 = $1{\times}105$

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.