We've all experienced the fluid-dynamics phenomenon known as the "teapot effect." Every time you pour out a nice relaxing cup of tea, a little of the elixir dribbles down the outside of the spout of the teapot, dampening your doily and your spirits.
It happens because liquid clings to the lip of the spout instead of exiting neatly, especially at low rates of flow.
Cyril Duez and his team of fluid dynamicists could not tolerate one more dribble. They have identified the root cause, a "hydro-capillary effect" that makes the tea fail to leave the spout material gracefully. Two techniques can be used to combat this.