Leaping shampoo glides on a lubricating air layer

S. Lee, E. Q. Li, J. O. Marston, A. Bonito, S. T. Thoroddsen
2013 Physical Review E  
When a stream of shampoo is fed onto a pool in ones hand a jet can leap sideways or rebound from the liquid surface in an intriguing phenomenon known as the Kaye effect. In earlier studies it has been debated whether non-Newtonian effects are the underlying cause of this phenomenon, making the jet glide on top of a shear-thinning liquid layer, or whether an entrained air layer is responsible. Herein we show unambiguously that the jet slides on a lubricating air layer. We identify this layer by
more » ... ooking through the pool liquid and observing its rupture into fine bubbles. The resulting micro-bubble sizes suggest this air layer is of sub-micron thickness. This thickness estimate is also supported by the tangential deceleration of the jet during the rebounding.
doi:10.1103/physreve.87.061001 pmid:23848618 fatcat:2qsk32pp7raixpreszrp32psau