Figure 8-30-D

Liquid in square bundle of 16 non-uniform rods.

The contact angle on the inner rods is 150 degrees and 10 degrees on the outside rods. The gap between the rods is one rod radius. The liquid advances on the outer rods and wets the outer parts of the inner rods, but the liquid retreats inside the inner rods. See this interactive app to explore liquid wicking in rods,