开槽对管内填充金属泡沫对流换热的影响

Convection Heat Transfer Performance for Rectangle Channel Inserted with Metal Foam Involving Slotting Impact

采用数值模拟方法建立计算机CPU翅片散热器相同尺寸的金属泡沫模型,研究了矩形管内插入金属泡沫后的流动和换热性能。研究表明,数值模拟结果与文献实验结果吻合较好;开槽深度对金属泡沫换热性能具有明显影响,在低雷诺数下,努塞尔数随着无因次高度H/D(开槽深度和迎风面水力直径比值)的增加而减小;在高雷诺数下,努塞尔数随着H/D的增加先增大后减小,H/D在0.146~0.438范围内,努塞尔数比不开槽金属泡沫的大。引入基于渗透率的雷诺数整理数据得到了管内填充开槽金属泡沫的强制对流换热准则方程。

A metal foam model with same size as the CPU fin radiator was established to numerically study the flow and heat transfer performance in a rectangle channel inserted with metal foam.The results show that the numerical simulation results agree well with the experimental results in the literature and the slotting depth obviously impacts the heat transfer performance.The Nusselt number decreases with the increase of the dimensionless height H/D(slotting depth to diameter ratio)in low Reynolds number range and the Nusselt number first increases and then decreases with the increase of the dimensionless height in higher Reynolds number range.When the dimensionless height increases from 0.146 to 0.438,the Nusselt number is found to exceed that of the full po-rous channel.And the Nusselt criterion describing convective heat transfer in foamfilled rectangle channel is finally obtained with Reynolds number based on permeability.