A Model for Coalescence in a Two-Dimensional Close-Packed Dispersion

The effect of a vertical force on the shape of a two-dimensional drop constrained by the presence of other drops in a horizontal row is considered. From the areas of the draining films above, below and to the side of the drop and the forces acting on them, the coalescence time may be calculated in relation to that of the draining film beneath a single drop subjected only to the weight of the drop. Calculations show that the coalescence time of a constrained drop decreases as the applied force increases, whereas that of an unconstrained drop increases. This suggests a relation between the height of a close-packed droplet dispersion and the coalescence time of a drop at the disengaging interface.