不同截面形状超疏水微肋阵内对流换热特性

通过在圆形、菱形以及椭圆形微肋阵表面固化含有微纳米颗粒涂层制备超疏水微肋阵，并对不同截面形状超疏水微肋阵内流动与对流换热特性进行实验研究，测量得到了超疏水处理前后各截面形状微肋阵内流动阻力系数f以及Nusselt数。此外，通过计算超疏水微肋阵内的综合传热强化因子ε，定量分析了超疏水处理对不同截面形状微肋阵内流动与换热特性的综合影响。研究结果表明，超疏水处理后圆形、菱形、椭圆形微肋阵内摩擦阻力系数与未处理前相比最大可降低72%、66%、70%；同时，3种截面微肋阵内Nu有所降低，且疏水前后微肋阵Nu偏差随加热功率的增加逐渐减小，高加热功率下3种微肋阵超疏水处理前后Nu偏差最大分别不超过44%、17%、47%；高加热功率下超疏水菱形微肋阵在Re<1200范围内具有良好的综合传热强化性能，ε始终高于1.17。

Convection heat transfer characteristics of super-hydrophobic micro pin-fins with different cross-sectional shapes

Super-hydrophobic micro pin-fins with circular, diamond and elliptical cross-sectional shapes were prepared by solidifying hydrophobic layers involved nano-particles on the flowing surfaces, and the flow resistance coefficient as well as Nusselt number in super-hydrophobic micro pin-fins was measured.The integrated effect of super-hydrophobic surface on resistance reduction and heat transfer enhancement was explored by analyzing the integrated heat transfer enhancement factor ε.The results indicated that the friction resistance coefficient was reduced at 72%, 66% and 70% in three kinds of micro pin-fins with super-hydrophobic walls and different cross-sectional shapes.Besides, although Nu in all three kinds of micro pin-fins was reduced, the value of the decrease was less than 44%, 17% and 47% under the high heating power in present research.In addition, the super-hydrophobic micro pin-fins with diamond cross-sectional shape had good comprehensive heat transfer enhancement performance under the high heating power, and the value of ε is higher than 1.17 in the range of Re<1200.