Flow characteristics of dilute polymer solutions in micro tubes

Pressure drops and velocity profiles for micro tubes were investigated for the laminar flow of distilled water and dilute polymer solutions. The test micro tubes were fused silica capillaries with diameters in the range of 50.2-251.8 mu m, and a value of l/d (length/diameter) of about 340. By performing pressure drop measurements, it is shown that the experimental data agree well with the Hagen-Poiseuille equation in the case of Newtonian fluids. On the other hand, the flow rate of dilute polymer solutions increases relative to that of distilled water in the low Reynolds number range. The increased flow rate ratio is a maximum of about 15% in the case of d = 251.8 mu m. For the result of the micro PIV measurement, however, there are few differences between the velocity profile of distilled water and the Peo 5 ppm solution.