Novel k-ω Turbulent Model for Prediction of Drag Reduction in Viscoelastic Fluid Flow

Abstract

One effective method for reducing pressure drop in turbulent pipe flows is the injection of Drag Reducing Agents (DRA), a technique that has been used for over 70 years. This study investigated the modeling and simulation of turbulent pipe flow behavior by developing a novel k-ω turbulence model and utilizing the modified Generalized Newtonian Fluid (GNF) model to integrate the fluid's rheological properties. The focus was on turbulent pipe flows involving DRA, which exhibit viscoelastic non-Newtonian fluid properties. This new k-ω model was derived from mathematical modeling by using the non-Newtonian k-ε model. Computational Fluid Dynamics (CFD) software was used to simulate the derived equations, incorporating non-Newtonian terms that encompass the rheological properties of drag-reducing fluids. These terms were implemented into the software using User-Defined Functions (UDFs). To assess the accuracy of our results, we compared them with data from the open literature, demonstrating a significant improvement in the precision of our results. Our model exhibited good agreement with experimental data, with an average deviation of 10.53% in the friction factor predicted for the studied fluids. Furthermore, the model showed high accuracy in near-wall regions, particularly the viscous and buffer sublayers.