Drag reduction in a gravity‑driven fow system using polyethylene oxide solutions

Abstract

The current study describes the use of a mathematical formula based on macro-scale balances to calculate the efux time for gravity draining a Newtonian liquid from a large conical tank through an exit pipe at the bottom of the tank when the fow in the pipe line is turbulent. The least amount of time required to drain the tank will be calculated using the efux time equation, which has been modifed using experimental data. When the fow is mixed, that is, partially laminar and partially turbulent, gravity-driven, and once through the system, the percentage reduction in efux time that the addition of water soluble polyethylene oxide polymer has on drag reduction is displayed. Therefore, the efux time equation provides the shortest amount of time needed to acquire the liquid draining from the tank