脉冲宽度及质量流量对微尺度流动沸腾的影响

对通过微机械加工技术制成的微芯片进行微尺度过冷流动沸腾现象的研究，分析了脉冲宽度及质量流量对沸腾起始时间的影响.所用Pt微加热器尺寸为140 μm×100 μm，试验过程选用了6个脉冲宽度（0.05、0.10、0.20、0.60、1.00和2.00 ms）及5种质量流量条件（45、90、135、180和225 kg/(m3·s)），结果表明：脉冲宽度和质量流量对绝对沸腾起始时间影响不大；通过试验数据得到不同脉冲宽度下各个区域的转变关系式，以及对本试验最有效的脉冲宽度为0.20 ms.

Effect of Pulse Width and Mass Flux on Microscale Flow Boiling

The investigation on microscale flow boiling of subcooled water was carried out based on the microchip fabricated by MEMS technology. The effects of pulse width and mass flux on boiling inception were analyzed. A Pt microheater (140 μm×100 μm) was used in this experiment. Six pulse widths (0.05, 0.10, 0.20, 0.60, 1.00 and 2.00 ms) and five mass fluxes (45, 90, 135, 180 and 225 kg/(m3·s)) were chosen during experiment. It is found that either pulse width or mass flux has little effect on boiling inception time. An expression which for the transition heat flux of boiling regimes under different pulse width fits well with experimental data is obtained. A most effective pulse width is obtained through the analysis on non dimensional boiling inception time.