Distilled water and tetrachloromethane, used as the working fluid, flowed through the smooth quartz glass microtube with inner diameter of 19.60 μm. The single tube and double tube methods were used to measure the pressures and temperatures of the inlet and outlet of microtube.The flow rates and flow resistances in microtube were obtained when the Reynolds number varied from 9.6 to 530 and were compared with the classical theoretical values. The investigation showed that the viscous dissipation decreased the friction factor by about 13.7%. However, the pressure drop of the inlet and outlet of microtube, the entrance effect and the electrical double layer effect (EDL effect) increased the friction factor by 16.12% and 6.84%, repectively. Moreover, the friction factor was approximately equal to those predicted by the Hagen Poiseuille in 19.6 μm if neglecting those microscale effects.
