Two phase flows under the coating blade

Modeling the blade coating process is important because of the high speeds, narrow gaps, and opaque nature of the process. The influence of colloidal forces on the motion of particles is reported using a Stokesian dynamics me thod. Strong long-range repulsive forces between particles lead to layers o f particles and ordered motion of the particles under the blade. When this repulsive force is short range, particle structures form that give larger f orces on the blade, a buildup of panicles near the stagnation point, and st ructures that span the distance between the paper and the blade. Convention al van der Waals forces are not strong enough to hold particles together in to a structure when subjected to the hydrodynamic forces. Strong attractive forces lead to particle clusters that will bridge the gap between the pape r and the blade and disrupt the flow field.