Effects of hydrodynamic interaction on random adhesive loose packings of micron-sized particles

Random loose packings of uniform spherical micron-sized particles under a uniform flow field are investigated via an adhesive discrete-element method with the two-way coupling of both the particles and the fluid. Characterized by a dimensionless adhesion parameter $Ad$, the packing fraction follows the similar law to that without fluid, but results in larger values due to the hydrodynamic compression. The total pressure drop through the packed bed increases with the packing fraction and agrees well with the theoretical predictions of Ergun function. The effects of different parameters, such as flow velocity, particle size and surface energy, on packing fraction and pressure drop take place through different ways, which can be associated with the local mechanical equilibrium in the presence of fluid.