In many powder handling processes in industry, including wet granulation and particle coating, liquid is often added to dry powder for various purposes. The formation of liquid bridges imparts additional bonding forces between particles, which can drastically change the flow dynamics. We have proposed several liquid bridge force models to simulate wet particle behaviour as demonstrated in the example above.

Surface adhesion forces can be more dominant than gravitational forces for fine powders, which can significantly alter the packing behaviour and the resultant bulk density. We have numerically proven that the packing behaviour can be largely influenced by the surface energy density as well as the configurations of falling clusters.

There are many unit operations that require mechanical handling of fine and cohesive powders. The interaction between particles and moving walls can lead to wall make-ups and dead zones, which have negative impacts on the quality of final products. Numerical simulations can provide detailed information about the internal flow field and help optimise both tool design and operation conditions.