#teapot effect

[fuckyeahfluiddynamics]

Solving the Teapot Effect

The teapot effect -- that tendency for liquid to dribble down the outside of the spout when pouring -- is a frustration to many tea drinkers. Unraveling the fluid dynamics of this phenomenon has taken various researchers decades, but a team now believe they've captured the problem fully.  (Image credit: S. Ferrari; video and research credit: B. Scheichl et al.; via Ars Technica; submitted by Kam-Yung Soh) Read the full article

[fuckyeahfluiddynamics]

Tea lovers have long been frustrated by the tendency of liquid jets to adhere to solid surfaces -- the so-called teapot effect that makes the last vestiges of every pour drip down the spout. By investigating the effect with vertical rods, researchers found that, at low enough flow rates, a liquid jet is able to adhere completely, forming a liquid helix that coils around the rod. The authors were also able to construct a mathematical model to capture the behavior. They concluded that both the wettability of a surface and the curvature of the solid are critical to determining whether or not a liquid jet will stick. (Image and research credit: E. Jambon-Puillet et al.; via APS Physics; submitted by Kam-Yung Soh)