具有非均匀内热源的多孔介质中自然对流传热的数值研究  

Numerical study of natural convection in a porous vertical annulus with a nonuniform heat source

作　　者：李栋[1] 王煤[1] 余徽[1] 胡慧杰[1] 

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《计算机与应用化学》2006年第7期635-638,共4页Computers and Applied Chemistry

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.

关 键 词：多孔介质 自然对流 非均匀内热源 数值分析 

分 类 号：TQ021.1[化学工程] O357.3[理学—流体力学]