微通道正弦型底面结构对局部流动和传热特性的影响

Effect of Sinusoidal Bottom Wall Structrue on Local Flow and Heat Transfer Characteristics in A Microchannel

为研究微通道的正弦型底面结构对流动和传热性能的影响,设计了5种正弦型底面结构的微通道,并采用数值模拟方法研究其在不同雷诺数下通道内局部流动情况和传热性能。结果表明,正弦型微通道内存在二次流;正弦型微通道内局部压力、泊肃叶数、壁面温度和努塞尔数沿着流动方向都出现波动的趋势,但后两者较平缓。在所研究的雷诺数范围(230~1060)内,正弦型微通道平均泊肃叶数随着雷诺数增大而增大;部分正弦型结构微通道在雷诺数不大于600时,平均努塞尔数略低于光滑通道,说明传热效果有所降低;在雷诺数大于600时,所有正弦型通道的平均努塞尔数大于光滑通道,表明传热效果较好。

In order to investigate the influence of sinusoidal bottom wall structure on the flow and heat transfer characteristics,five types of microchannel with sinusoidal bottom wall(MCSBW)were designed.The numerical simulation method was used to study the local flow and heat transfer performances in these microchannels at Reynolds numbers of 530 and 1060.Results showed that the secondary flow appears in the MCSBW.The local pressure,Poiseuille number,wall temperature and Nusselt number along flow direction presented a fluctuated trend in the MCSBW,but the latter two were slight.In the range of Reynolds number(230~1060),the average Poiseuille number of sinusoidal microchannels increases with the increase of Reynolds number.When the Reynolds number of sinusoidal microchannels is less than 600,the average Nusselt number is slightly lower than that of smooth microchannels,which indicates that the heat transfer effect is deteriorated.When the Reynolds number is greater than 600,all the average Nusselt number of sinusoidal channel is larger than that of smooth channel,which indicates that the heat transfer effect is better.