Forced wetting in a square capillary

Abstract

Corners formed between any two surfaces enhance the capillary flow along the corners resulting in the rise of thin liquid streams known as rivulets. In this work, we investigate the rivulet dynamics inside a square capillary under forced wetting. The continuously rising rivulets start decreasing in length linearly when the force is first applied and eventually reach a finite length above the central region of fluid in the capillary. We explain our observations using a simple model based on capillary rise.