中文摘要：

本文实验研究了平行多微通道入口处的特殊突缩结构所引起的单相气体流动压力损失。通过测定压缩空气流经通道入口前后的温度、压力和流量，得到了压力损失系数与单个微通道内流体Re数（3100-19000范围内）之间的关系式，与相关文献结果对比发现，现有的基于常规尺寸和微细尺寸的单通道突缩压降系数经验关联式不能正确预测平行多微通道入口突缩压力损失系数随Re数的变化。另外该关联式还能较好地预测饱和水蒸气的单相流动突缩压降系数。

英文摘要：

Single phase flow pressure drops caused by abrupt contraction at entrance of parallel multi-microchannels were investigated experimentally. Pressure and temperature before and after the entrance of multi-microchannels have been measured using compressed air and steam as working fluids. The results indicate that the existing correlations commonly used to predict the abrupt contraction pressure drop coefficient in single channel with commercial and small size cannot reasonably predict its trend for the case of this paper. A new empirical formula for the abrupt contraction pre~ure drop coefficient Kc against Reynolds number （range from 3100 to 19000） in one single micro-channel for air has been correlated, and its availability has been tested by the pressure drop data of saturated steam single phase flow.