摘要
采用数值计算和流动显示方法,对矩形封闭空间内水平放置三根电缆所引起的自然对流,在Gr~*=9.2×10~4—6.5×10~6范围内进行了理论和实验研究。结果表明,这种情形下的自然对流流动存在着环流。在低Gr~*数时,在电缆上方形成主环流;随着Gr~*数的增大,在电缆间出现涡流;在Gr~*=6.5×10~6时,电缆间出现成对的涡流。实验结果表明,硬脂酸锌粉粒是显示空气自然对流流动的比较理想材料。采用伪非稳态变系数方法是保证计算收敛而又节省机耐的有效方法。计算结果为设计该类型电缆的最大允许载流量提供了依据。
Experimental and numerical investigation on natural convection in a rectangular enclosure with three horizontal power cables in the range of Gr = 9.2×104-6.5×106 has been reported. Two different circulations were visualized: main stream is large and circulate clockwise; the other is a smaller vortex circulated anti-clockwise. With the decrease in Gr, the anti-clockwise vortex becomes smaller in dimension and weaker in rotation. The bouyancy force at Gr = 6.5×106 lead to forming a pair of vortices between the power cables. Zinc stearate particles has proved out to be a good trace material for visual display of natural convection flow pattern in enclosure. Using the method of the false transient, the computer time for solving equations (1)-(6) can be substantially reduced and the stability of numerical iteration process can be ensured. The obtained results provide a theoretical basis for designing the ampere-capacity of the power cables in covered tray.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
1989年第4期407-411,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金
