Experimental investigation of the exit dynamics of a horizontal circular cylinder out of water and silicone oil

A dolphin leaping out of the water. A piece of bread pulled from Swiss fondue. A car emerging from a bath of anti-corrosion fluid. More somberly, a missile launched from below sea level. The question is: how much liquid is carried along? We study the entrainment around a horizontal cylinder and observe that, whether in water or in oil (50 times more viscous than water), higher speeds result in greater liquid entrainment. By tracking the thickness of the liquid film at the top of the cylinder, we measure the drainage process down to a few microns. Remarkably, shortly after crossing the interface (typically within 1 second), the drainage becomes independent of the withdrawal speed.