扇形穴-梯形肋微通道散热器层流与传热特性

Laminar Flow and Heat Transfer Characteristics of Microchannel Radiators with Fan-shaped Cavities and Trapezoidal Ribs

提出了一种新型扇形穴-梯形肋微通道散热器,采用单变量方法从速度、压降和温度方面分别对比了单一空穴或肋与组合结构的性能。基于强化传热因子和熵产最小法对微散热器进行了整体评估。结果表明:空穴和肋的组合使用,使得边界层周期性地中断和再发展,空穴和肋组合的散热效果优于单一的肋或穴。在雷诺数(Re)为1 300时,强化传热因子为1.535 4,远高于梯形肋的1.355和扇形空穴的1.28。熵产分析表明,组合结构的不可逆损失最小,这与强化传热因子结果相一致。

A new type of fan-shaped cavity and trapezoidal rib microchannel heat sink is proposed.The performance of single cavity or rib and composite structures were compared by the univariate method in terms of velocity,pressure drop,and temperature.Based on enhanced heat transfer factor and entropy minimization method,the overall evaluation of micro radiators with different structures was carried out.The results show that the combined use of cavity and rib makes the boundary layer periodically interrupted and re-developed,and the combined heat dissipation effect of cavity and rib is better than that of a single rib or cavity structure.When Re is 1 300,the enhanced heat transfer factor is 1.535 4,much higher than 1.355 for a trapezoidal rib and 1.28 for a fan-shaped cavity.Entropy generation analysis shows that the combined structure has the least irreversible loss,which is consistent with the enhanced heat transfer factor.