双绝热圆柱对水平三角腔内自然对流影响的数值研究

针对含双绝热圆柱的底部加热水平等腰三角腔内空气的稳态层流自然对流开展研究.通过有限容积法对控制方程进行了数值求解,其中瑞利数的变化范围为104 ～106,圆柱体的尺寸比则分别为0（无圆柱体）、1/8和1/4.基于计算结果对自然对流的流动与传热特性随瑞利数和尺寸比的变化规律进行了分析和讨论.结果表明,双绝热圆柱的存在较大程度上改变了三角腔内自然对流的流型和温度场分布,但对整体传热影响较小,仅略微提高了平均努赛尔数,强化传热的效果在尺寸比为1/8时较为明显.

Effects of the presence of a pair of insulated circular cylinders on natural convection in a horizontal triangular enclosure

The steadystate laminar natural convection of air from a pair of insulated circular cylinders to a bottomheated horizontal isosceles triangular enclosure was studied. The governing equations were solved numerically using the finite volume method. The Rayleigh number was varied from 104 to 106 and the aspect ratio was set to 0 （in the absence of in ner cylinders） , 1/8 and 1/4. Based on the numerical results, variations of the natural convective flow and heat transfer were analyzed as functions of the Rayleigh number and aspect ratio. It was shown that the natural convective flow patterns and temperature distributions in the triangular enclosure were significantly modified due to the presence of the inner insu lated cylinders. The overall heat transfer, however, was almost unaffected with the average Nussclt number being only slightly increased. The most pronounced heat transfer enhancement was achieved when the aspect ratio was 1/8.