摘要
采用数值方法分析了填充多孔介质的竖直同心套管内,非均匀分布的内热源和内外壁面温差对自然对流的影响。考察了高宽比A、内热源分布系数m以及内外Rayleigh数之比Rai/Ra对流场、温度场和内外壁面Nusselt数的影响。结果表明：Rai/Ra较大时流场中部形成逆向环流,并出现θ＞1的高温区；内壁面Nusselt数呈现先增大后减小的趋势,大约在Z=0．8处出现转折。外壁面Nusselt数在Z＞0．8处变化加剧,表明外壁面对流传热主要集中在管上部区域。m增大流体中心逆向环流随之减小并最终消失。
A numerical analysis is conducted for natural convection in the vertical annulus filled with saturated porous medium with a non-uniform generation. The effects of high/width ratio, heat generation coefficient and Rai/Ra on the flow, temperature, local and average Nusselt numbers are investigated. The results show that reverse circulations appear in the velocity field center and a region of θ 〉 1 occurs in the temperature field at relatively high Rai/Ra. The Nusselt number on the inner wall increases with increasing Z at first, and then turn down at Z = 0.8. On the other hand, the outside Nusselt number increases sharply at Z 〉 0.8, and convective heat transfer mainly occurs on the upper of annulus. The reverse circulations in the center of the velocity field decrease and even disappear with increasing m.
出处
《计算机与应用化学》
CAS
CSCD
北大核心
2006年第7期635-638,共4页
Computers and Applied Chemistry
