Drag reduction and degradation by sodium alginate in turbulent flow

Abstract

The utilization of drag-reducing polymers has long been hindered by their irritancy, corrosiveness, and toxicity across various domains. In this investigation, we explored sodium alginate, a natural drag reducer, for its efficacy in reducing drag and its resilience to shear in millimeter-scale pipelines. Initially, an experimental setup was devised to assess the drag reduction capabilities of sodium alginate at varying concentrations and flow rates using Response Surface Methodology (RSM). The relationship between drag reduction ( DR ), concentration ( C ), and flow rate ( Q ) was established by analyzing the experimental data. Subsequently, variance analysis was employed to validate the data accuracy, with a comparison between predicted and experimental DR values revealing an error margin within ± 20%. Analysis of cyclic shear testing of sodium alginate solution in tubes demonstrated its effectiveness as a shear flow drag reducer. Furthermore, results from laser particle size analysis indicated minimal molecular breakage of sodium alginate during cyclic shear.