多孔鳍歧管微通道流动传热特性研究

Flow and Heat Transfer Characteristics in Manifold Microchannel with Porous Fins

微通道技术是芯片冷却最具前景的技术之一。本文采用数值模拟的方法对比分析了不同孔隙率(ε=0.2~0.8、ε-rise和ε-drop)多孔鳍歧管微通道流动传热特性。结果表明:多孔鳍可以显著降低歧管微通道流动阻力,最高超过20%。但随着入口速度增加,压降降低效果逐渐减弱。在研究的孔隙率变化范围内,ε=0.4和ε=0.6的多孔鳍歧管微通道综合性能更好。基于芯片最高温度评价,ε-rise案例相比ε=0.4案例热阻更低,压降更高;且随着入口速度增加,热阻优势得到强化,压降劣势逐渐缩小。与ε=0.4案例相比,ε-rise案例在压降仅高1.4%的情况下,热阻降低8%。

Microchannel technology is one of the most promising technologies for chip cooling.In this study,the flow and heat transfer characteristics in manifold microchannels with different porosities(ε=0.2-0.8,ε-rise,andε-drop)of porous fins and solid fins were compared and analyzed using numerical simulation.The results showed that porous fins considerably reduced the flow resistance in the manifold microchannel by more than 20%.However,the pressure drop reduction effect decreased at larger inlet velocity.In the studied porosity variation range,the porous fins withε=0.4 andε=0.6 exhibited a better comprehensive performance.Based on the evaluation of the maximum chip temperature,ε-rise had a lower thermal resistance and higher pressure drop thanε=0.4.As the inlet velocity increased,the thermal resistance advantage of the porous fins withεrise was strengthened,and its pressure drop gradually reduced.Compared to theε=0.4 case,there was an 8%reduction in thermal resistance in theε-rise case,at the cost of only a 1.4%increase in pressure drop.