平板、离散式热源直角三角形腔内自然对流传热  

Natural Convection Heat Transfer in Right-angled Triangular Cavity with Flat Plate and Discrete Heat Sources

作　　者：齐润生 王子云[1] 任嘉友 吴玉玲 QI Runsheng;WANG Ziyun;REN Jiayou;WU Yuling

机构地区：[1]四川大学建筑与环境学院,四川成都610065

出　　处：《煤气与热力》2020年第7期16-20,34,I0042,共7页Gas & Heat

摘　　要：模拟斜边布置大平板热源、离散式热源的直角三角形腔内温度分布,对斜边上热源分布数量、斜边与底边的夹角对斜边、竖直边附近努塞尔数的影响进行数值模拟。三角形底边(直角边)绝热,竖直边为低温恒温冷边(以下简称竖直冷边)。斜边设置大平板(热源分布数量为1)、离散式(热源分布数量为2~4)恒温热源,除热源设置位置外,斜边其他位置的温度与竖直冷边一致。将斜边设置热源外的部分称为低温段,将设置热源的部分称为热源段。温度场分布:靠近斜边的空气向上流动,靠近竖直冷边的空气向下流动。大平板热源与离散式热源的热边界层形式与传热规律相似。随着热源分布数量增加,斜边附近空气温度分布更加复杂,斜边的热影响区域有扩大的趋势。随着夹角变化,三角形的几何结构发生变化,三角形内自然对流的范围及强度受到影响,但总体规律基本一致。局部努塞尔数:热源段与低温段交接处附近局部努塞尔数比较大,热源段中间部分附近局部努塞尔数比较小。越接近三角形顶点(斜边与竖直冷边的交点),热源段与低温段交接处附近局部努塞尔数增大。不同热源分布数量的竖直冷边附近局部努塞尔数均呈现先升高后下降的趋势。与斜边距离较远的竖直冷边附近的自然对流传热强度比较弱,与斜边距离较近的竖直冷边附近的自然对流强度比较强,而三角形顶点基本不存在自然对流传热。夹角越小,热源段与低温段交接处附近局部努塞尔数越大,热源段中间部分附近局部努塞尔数越小。不同夹角的竖直冷边附近局部努塞尔数均呈现先升高后下降的趋势。夹角越大,竖直冷边附近局部努塞尔数越大。平均努塞尔数:相同条件下,斜边附近平均努塞尔数高于竖直冷边。热源分布数量一定时,斜边、竖直冷边附近平均努塞尔数均随夹角的增大而增大。夹角一定�The temperature distributions in right-angled triangular cavities with large flat plate heat source and discrete heat source are simulated,and the influence of number of the heat source distribution on the oblique side and the angle between the oblique side and the bottom side on the Nussel number near the oblique side and vertical side is simulated numerically.The bottom side(right-angled side)of the triangle is adiabatic,and the vertical side is a cold and constant temperature cold side(hereinafter referred to as vertical cold side).Large flat plate constant temperature heat source(the number of heat source is 1)and discrete constant temperature heat sources(the number of heat sources is 2 to 4)are set on the oblique side.Except for heat source setting location,the temperature of other locations on the oblique side is consistent with that of the vertical cold side.The part of setting the heat source outside the oblique side is called the low temperature section,and the part of setting the heat source is called the heat source section.Temperature field distribution:The air near the oblique side flows upward,and the air near the vertical cold side flows downward.The thermal boundary layer forms of large plate heat source and discrete heat source is similar to the heat transfer law.As the number of heat sources increases,the temperature distribution near the oblique side becomes more complex,and the area affected by heat sources tends to expand.As the included angle changes,the geometry of the triangle changes,and the range and strength of natural convection in the triangle are affected,but the overall rule is basically consistent.Local Nusselt number:The local Nusselt numbers near the junctions of heat section and cold section are relatively large,and the local Nusselt numbers near the middle parts of heat section are relatively small.The closer it is to the vertex of the triangle(the intersection of oblique side and vertical cold side),the larger the local Nusselt numbers near the junction are.The local Nusselt

关 键 词：直角三角形腔 大平板热源 离散式热源 自然对流传热 

分 类 号：K124[历史地理—历史学]