除湿条件下波纹通道内对流传热传质的数值研究

通过数值计算对紧凑换热器一种波纹翅片通道内除湿条件下周期性充分发展的对流传热传质情况进行数值研究。计算采用曲线坐标系下压力与速度耦合的SIMPLER算法,湿空气流动Re数的范围为100～1100,Pr数为0.71,Sc数为0.61。讨论了不同波纹高度、波纹间距对阻力与换热的影响,给出了不同Re数下的浓度场,并对动量、传热及传质进行了定量比较分析。计算结果表明,整体Nu数及fRe数随着波纹高度的增加或波纹间距的减小而增加;浓度随着Re数的增加沿着流动方向迅速降低;计算能较好的满足Chilton-Colburn相似,表明传热特性均可类推到传质特性中去。

NUMERICAL STUDY OF CONVECTIVE HEAT AND MASS TRANSFER IN WAVY CHANNEL UNDER DEHUMIDIFYING CONDITIONS

The periodically fully developed convective heat and mass transfer characteristics inside two-dimensional wavy channel were investigated numerically. Calculations were performed under dehumidifying conditions for humid air of Pr = 0.71, Sc = 0.61, in the range Re = 50 ~ 1100, based on SIMPLER algorithm in the curvilinear body-fitted coordinates. Effects different wavy heights, wavy distances, and concentration field under different Reynolds number on flow friction and heat transfer characteristics numbers were presented. Quantitative results for momentum, heat and mass transfer, under different fluid Reynolds were analyzed. The results show that the overall Nusselt numbers and friction factors increase with increasing wavy heights or decreasing wavy distances. Concentration of humid air drops quickly along the wavy channel. Chilton-Colbum analogies of heat and mass transfer almost hold well in all present practical calculations. It is found that the heat transfer characteristics insied wavy channel may be forwarded to that of mass transfer.