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Leaping Shampoo and the Stable Kaye Effect.

Scientists of the University of Twente in The Netherlands won a prestigious place in the 'Hall of Fame' of videos about fluid-in-motion.

They have made a video of leaping shampoo, in which they explain the so-called Kaye effect.

A. Kaye in Nature magazine in 1963 wrote "I can offer no explanation for this behaviour."

At high-speed recording of 1000 frames per second the following observations were made in 300ms interval:
1) a heap is formed, 2) a streamer ejects, 3) the outgoing jet rises, 4) hits the incoming jet, 5) ends the Kaye effect.

What causes the Kaye effect?!
Streamer ejects through shear-thinning property of fluid. A dimple is formed in the viscous heap. Outgoing jet is thicker quantitatively following continuity. The dimple deepens through a vertical force acting on the viscous heap and the jet rises.

The scientists set up a simple energy balance model. It includes viscous dissipation and the sear-thinning behavior of the shampoo in the dimple structure. Elastic properties of the fluid play no role.

The model predicts the leap height of the shampoo as a function of the release height. It even predicts a critical release height as observed in experiment. (For details see: JSTAT / 2006 / P07007)

To prevent the outgoing jet from interfering with the incoming jet the surface was tilted, leading to a stable Kaye effect cascade.

Leaping shampoo may even act as a light guide for laser beams in multitude of colors.

The people who worked on this are: Michel Versluis, Cor Blom, Devaraj van Meer, Ko van der Weele, Detlef Lohse.

This science video contains:
high resolution, kaye effect, shampoo, university of twente, netherlands, fluid in motion, heap, streamer, jet, dimple, force, energy balance model, fluid, laser, light guide