Bidisperse Aggregation and Gel Formation via Simultaneous Convection and Diffusion

Stochastic simulations are performed for two-component transport-limited aggregation processes with Brownian motion and shear contributing to the collision frequency. To study the effects of both mechanisms, the radius ratio of the initially pure particles is 1:8 on average, with the larger particles having sizes on the order of microns (μm). For a mixed orthokinetic−perikinetic kernel, the kinetics of the aggregation process and gel point are shown to have a cooperative dependence on shear and the relative concentration of large particles to small ones. This was found to be a result of the shear sensitivity of the aggregation process to the addition of large particles. Ultimately, it is shown that accurate prediction of the kinetics and gel points of complex aggregation phenomena requires the use of the stochastic approach to the aggregation kinetics upon which the simulations are based.