圆形和跑道形微通道内空气换热特性数值研究

采用数值模拟的方法对不同管径、不同长度微圆管的换热特性和换热能力进行了研究和对比。结果表明:对于相同管长的圆管,在相同压比条件下,除了内径为0.1mm的圆管外,单位流通面积的换热量随着管径的增大而逐渐减小;在相同压比条件下,除内径为0.1mm的圆管外,其他圆管的单位面积换热量均随管长的增加而增大,且较大管径的增大幅度明显大于较小管径的增大幅度。对当量直径相同的圆管和跑道形管进行对比发现,圆管的换热能力明显优于跑道形管道。

Numercial Research on Heat Transfer Characteristics of Air in Circular and Race Track Shaped Micro Channel

The heat transfer characteristic of the airflow through circular micro-channels with different diameters and lengths are investigated by the numerical simulations. The results show that, in addition to the circular channel with diameter 0.1mm, the heat transfer intensity of unit flow area decreases with the diameter increasing of circular channel for the same channel length under the same pressure ratio; the heat transfer intensity of unit flow area increases with the increasing of channel length, and the heat transfer intensity of unit flow area increases more quickly in large diameter than that in small diameter for the same pressure ratio, except the one with diameter of 0.1mm. The heat transfer capacity of circular channel has a significant advantage over the race track shaped one with the same equivalent diameter from the result of the comparison.