A layer of shampoo is vibrated in a petri dish at 60Hz. Depending on the oscillation amplitude, several phenomena are observed. Most interesting, is the formation of a stable rolling column, documented in this video. Column is made from two adjacent rolls, with fluid flowing down the center of the column and up at the edges. Circular flow cells can be formed if the column is not in contact with the dish’s walls.
I built this apparatus to investigate the vibration of shear-thickening particulate suspensions (high-mass fraction cornstarch solutions) but decided to try out shampoo because it was a shear thinning fluid. I think the explanation lies in the shampoo’s high-viscosity and shear-thinning property. I just observed this for the first time minutes ago, and haven’t come up with any explanation yet. Also, the shampoo gets opaque after vibration – I think it may even be forming a very soft foam.
Duration : 0:1:58
