Use of Polymer Solutions for Drag Reduction in Gravity Driven Flow Systems

Abstract

Efflux time measurements are carried out for draining water, a Newtonian liquid (below its bubble point) from a large open cylindrical tank under the action of gravity through an exit piping system. The mathematical models reported in the literature for Newtonian liquid are used for verifying the validity of experimental data. Further, to reduce the efflux time (i.e. to reduce drag), measurements are also carried out in the presence of water soluble drag reducing polythene oxide polymer solutions. The variables considered for both the cases (with and without polythene oxide polymer solutions) are diameter of storage vessel, initial height of liquid in the tank, length of the exit pipe, diameter of exit pipe and concentration of polymer. The experimental data suggested that as the diameter of exit pipe is increased, addition of polymer solutions do not have a significant impact on efflux time. This also suggests that effect of polymers is felt at the contraction point only.