Modelling and simulation

Description

Many powder processes (conveying, packing, filling, mixing, etcetera) result in small changes in the particle shape. They can therefore be effectively modeled at the particle level, usually with the discrete element method (DEM) assuming independent contacts between the particles. Tableting causes extensive particle deformation, however, making this unit operation more difficult to model. In particular, contacts are no longer independent.

A central theme of our research has been to develop nonlocal contact models and simulation methods that will enable efficient and accurate particle-scale modelling of powders at high relative density. Continuum modelling is used to address various aspects of powder compression, such as the influence of friction on the unloading curve and thermodynamic consistency of the underlying constitutive model.

The DEM has been used to determine effective properties of adhesive units, the “building blocks” of adhesive mixtures commonly used to deliver inhaled medicines. We have also developed models for coupled dissolution and permeation/absorption and of dissolution of polydisperse materials.