Hydrodynamic drag and electrophoresis of suspensions of fractal aggregates

The hydrodynamic properties of fractal aggregates are investigated numerically by solving the three-dimensional Stokes equations. Aggregates are built with a variety of sizes and fractal dimensions. Their hydraulic radii conductivities and mobilities are evaluated as functions of their volume fraction in the suspension. An influence of the fractal dimension is visible on the hydrodynamic and electrokinetic characteristics of the aggregates. In the dilute limit, our results compare well with the predictions of various mean-field arguments.