摘要
对内壁面局部恒温加热,外壁面恒温冷却,其它壁面保持绝热条件下的竖直同心套管内多孔介质中的自然对流进行了数值研究,分析了瑞利数Ra、半径比κ及高宽比A对流场和温度场、内外壁面局部努塞尔数和加热段的平均努塞尔数的影响。研究结果表明:Ra及κ对速度和温度的分布影响显著,随着Ra和κ的增加,环流中心向上部和外壁面偏移,上部流速度远大于下部。内壁面加热段局部努塞尔数沿Z方向降低,但随κ的增加而增加;外壁面的局部努塞尔数变化与内壁面相反。加热段平均努塞尔数Nui随Ra及κ的增加而增加,根据计算结果得到了平均努塞尔数与瑞利数的关联式Nui=mRan。
Natural heat transfer and flow patterns in a cylindrical annulus filled with saturated porous medium were numerically studied. The inner wall of the annulus is heated locally at constant temperature and the outer wall is isothermally cooled in order to simulate the electronic element heat process. Numerical results show that effects of Ra and κ on the tempreture and velocity fields are significant. The center of core flow moves to upper and outer wall as Ra and κ increase and convective velocities are higher in the upper half than the lower half of the annulus. The local Nusselt number on the heated wall increases as κ increases and decreases as Z increases, and the case is reversed on the outer wall. The average Nusselt number on the heated wall increases as Ra and κ increase and the average Nusselt number is correlated by a relation of the form Nui=mRan.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
2003年第6期45-48,共4页
Journal of Sichuan University (Engineering Science Edition)
