(251e) Effect of Electrical Field and Radius Ratio on the Effective Angular Velocity for Couette and Poiseuille Flows

Different device geometries and flow regimes have been shown to have different effects on the solute separation process of pharmaceuticals and metabolites. Electrical field flow fractionation (EFFF) has been one area of interest to researchers, with a number of parameters being examined. With much of the previous research based on simple geometries, more recent work has expanded the breadth of knowledge to cylindrical devices. The typical approximation of this problem to a rectangular channel has been relaxed to access the role of radius ratios on the velocity field. The main focus of this contribution is to compare the effective angular velocities of Couette and Poiseuille flow regimes in cylindrical EFFF devices. In both situations, due to mathematical complexities, the analytical solution was explored using the spatial area-averaging methodology. This approach will be thoroughly described and several numerical examples will illustrate the most important variations of velocity with the electrical field and radius. The reported findings are expected to assist in product design and development as well as in experimentation.