Modeling the distributive mixing in an internal batch mixer

Mixing has been the focal point of many experimental studies in recent year s, but advances in modeling and simulation now allow for fast, accurate and useful simulation analysis. Numerous mixing indices have been developed bu t the majority are tailored to experimental studies. lit this study, a new mixing index is developed to analyze the particle position history of the m ixer. Due to its simplicity when dealing with moving boundary problems, the boundary element method is employed to model the fluid flow and track part icles. Numerous geometries can be modeled and compared on a basic workstation. Fir st the mixing index is applied to Couette flow. Analytical and boundary ele ment simulation results compare well. Next the method is used to analyze th e mixing capabilities of a Banbury mixer with different speed ratios. Furth er the mixing index is used to compare the mixing capabilities of triangula r mixing lobes versus typical Banbury type.