A mathematical model for laminar displacement of one non-Newtonian fluid by another in horizontal concentric annuli

This paper develops a mathematical model and a computational algorithm, whi ch enable the prediction of laminar displacement efficiency in concentric h orizontal annuli. Power-law model is used to characterize rheological prope rties of both displaced and displacing fluids. This model allows a careful investigation of individual effects of various parameters such as fluid rhe ology, flow geometry and displacement rate on the displacement efficiency. Simulated results demonstrate the dominant influence of rheological propert ies of displaced and displacing fluids on the laminar displacement efficien cy. The model can be used to optimize fluid flow parameters in chemical pro cess designs.