中文摘要：

实验研究了微通道内去离子水的流动阻力特性,微通道当量直径范围De=0.210～1.069mm,雷诺数范围Re=102～104,截面形状分为矩形、半圆形及三角形.通过测量微通道沿程压降及出、入口局部压降随流量变化关系,获得了沿程阻力系数及局部阻力系数.结果表明：当截面形状相同时,摩擦阻力系数随着当量直径的减小而降低;当量直径接近,截面形状不同时,其摩擦阻力系数也不相同;进、出口局部阻力系数变化趋势一致,且入口局部阻力系数要比出口的大;流型发生转变的临界雷诺数Rec=600～1 000.

英文摘要：

The flow characteristics of deionized water in microchannels investigated experimentally.The hydraulic diameter of microchannels range from 0.210 to 1.069 mm,and the Reynolds number range from 102 to 104.The cross-section is comprised of rectangular,semicircular and triangular.The pressure drop along microchannel and local pressure drop at inlet and outlet are measured and the friction factor and local resistance coefficient are obtained.Results show that the friction factor decreases with decreasing hydraulic diameter under the same cross-section geometry.The friction factor is also different with cross-section geometry even if the hydraulic diameter is similar.The variation trend of local friction factor at inlet and outlet are consistent in microchannels,but the values of friction factor at inlet are bigger than at outlet.The result also shows that the critical Reynolds number of flow pattern transition range from 600 to 1 000.