Figure 3-23-B

Liquid filament inside a curved wall.

The contact angle on all surfaces is 40 degrees, so Concus-Finn filaments can form. This model just has a filament along the outer curve of a curved channel (the vertical wall is not shown). Note that the filament does expand arbitrarily high and wide, since there is no catenoid surface that has the prescribed contact angles. The lesson from this and the previous model is that concave walls are more friendly to liquid spread than convex walls (apart from the shorter distance along the inner wall in