Entrance effects and slip flow corrections for flow of newtonian liquids through small glass capillaries

Abstract

Flow rate tests of distilled water, standard viscosity oil S-3 and a 5 ppm polyacrylamide (Separan AP 30) solution were conducted through horizontally mounted glass capillaries of radii 0.01012 cm and 0.0296 cm and lengths 5.047 cm and 30.06 cm, respectively, discharging to the atmosphere. Pressures as high as 11.4 x 105 dynes per cm2 (ca. 1.4 atmospheres) were achieved using a liquid head plus applied N2 pressure, giving shear rates as high as 1.3 x 105 sec-1 and Reynolds' numbers in the range of 10.2 to 666.8. In order to describe the flow, modifications were made to the Hagen-Poiseuille equation to account for slip flow and entrance-exit effects, which made the laminar flow equation EQUATION GOES HERE This study determined the values for 'm', the entrance-exit correction factor, and 'K', the slip flow coefficient. The best value for 'm' was found to be 2.29 for all the fluids studied. The 'K' values for distilled water and standard viscosity oil S-3 were found to be 12.03 x 10-4 cm and 8.09 x 10-4 cm, respectively. Results of the 5 ppm polyacrylamide tests showed that polymer addition does not increase the 'K' value of distilled water,