Figure 2-27-B: Filaments moving down channel with enlargements, not merging

Channel with three bulges.

The narrow parts of the channel are narrow enough to support bulk liquid progress, and narrow enough that separate Concus-Finn filaments cannot form. The bulges are too wide for bulk progress, so the filaments separate there and re-combine beyond the bulge. The contact angle on all surfaces is 30 degrees, so Concus-Finn filaments can form. The difference from Fig. 2-27-A is simply that the height of the wall has been raised a bit. The liquid in a bulge settles into approximately a catenoid shape, with a bare spot in the middle.