封闭空腔内耦合的自然对流传热:两个竖直导热壁的影响

CONJUGATED HEAT TRANSFER OF NATURAL CONVECTION IN ENCLOSURES ——EFFECT OF THE TWO VERTICAL CONDUCTION WALLS

本文描述具有两个竖直导热壁的封闭空腔内非稳态、二维、层流自然对流换热的数值分析结果。计算参数范围为Rα=10~4～5X10^6,0.1～43.6,K~*=1～100,t~*=0.11～0.40。给出了速度场和温度分布,得到了热壁和冷壁的平均和局部努谢尔特数,确定了相对于总温差和冷热壁内侧温差的努谢尔特数比的时间历程,并定义了冷壁传热的滞后时间概念,结果表明这些参数显著地受导热壁物性的影响。

Unsteady and steady, two-dimensional, laminar natural convect-icn heat transfer has been numerically investigated for the square enclosure formed by two vertical finite conductance walls and two horizontal zero-thick adiabatic walls. The calculated parameters cover a range of Ra from 10~4 to 5×10~6, a from 0.1 to 43.6, k from 1.0 to 100.0 and t from 0.11 to 0.40. The velocities vector plots, temperature profiles and the history of the ratio of the Nusselt numbers have been given out. The hysteresis time of heat transfer on the cold surface defined. The average and local Nusselt numbers obtained. The results show that the natural convection heat atansfer in enclosures is significantly influenced by the physical properties of walls.