3D打印三层微通道冷板的综合特性研究

Study on Comprehensive Characteristics of a 3D Printing Three-layered Microchannel Heat Sink

3D打印技术在快速成型和制造复杂结构零件方面具有巨大的优势。文中采用3D打印工艺制备了3种微通道散热器,分别是2种开放型的单层微通道和1种封闭型的三层微通道。对三层微通道散热器(Three-Layered Microchannel Heat Sink, TLMHS)的力学性能进行了压力测试。通过实验和数值仿真研究了50~780雷诺数范围内和恒定热通量条件下,三层微通道的流动和传热特性。通过实验和数值结果的对比,评价了3D打印工艺产生的粗糙壁对压降和传热的影响。结果表明,粗糙壁面对压降的影响总是负的,但随着雷诺数的增加,粗糙壁面对传热的影响由负向正变化。通过定义能量和流量效率因子,对传热强化进行了量化分析,发现当雷诺数为244时,泵功率对传热的强化效率最高,且存在1个泵功率阈值,使得其对传热的强化不可持续。

3D printing technology has huge advantages in rapid prototyping and fabricating parts with complex structures.Three microchannel heat sinks are fabricated by 3D printing process,which contain two open single-layer microchannels and one closed triple-layer microchannel.A pressure test is carried out for checking the mechanical property of the three-layered microchannel heat sink(TLMHS).The hydrodynamic and heat transfer characteristics of TLMHS are investigated by experiment and numerical simulation under the conditions of constant heat flux and Reynolds number ranging from 50 to 780.By comparing the experimental and numerical results,the influence of rough wall caused by 3D printing process on pressure drop and heat transfer is evaluated.The results show that the effect of rough wall on pressure drop is always negative,but that on heat transfer changes from negative to positive as Reynolds number increases.The heat transfer enhancement is quantitatively analyzed by defining the efficiency factors of energy and flow rate.It is found that the pump power is most efficient for heat transfer reinforcement when the Reynolds number is 244 and there is a pump power threshold that makes it unsustainable for heat transfer reinforcement.