Experimental observation of shear thickening oscillation

TL;DR

This paper reports the first experimental observation of shear thickening oscillation in a dilatant fluid, confirming theoretical predictions through experiments with a starch-water mixture showing oscillations around 20 Hz.

Contribution

The study provides the first experimental evidence of shear thickening oscillation, validating a previously theoretical phenomenological fluid dynamics model.

Findings

Observed shear thickening oscillation at ~20 Hz

Confirmed theoretical predictions with experimental data

Demonstrated oscillation in a density-matched starch-water mixture

Abstract

We report experimental observation of the shear thickening oscillation, i.e. the spontaneous macroscopic oscillation in the shear flow of severe shear thickening fluid. The shear thickening oscillation is caused by the interplay between the fluid dynamics and the shear thickening, and has been predicted theoretically by the present authors using a phenomenological fluid dynamics model for the dilatant fluid, but never been reported experimentally. Using a density-matched starch-water mixture, in the cylindrical shear flow of a few centimeters flow width, we observed strong vibrations of the frequency around 20 Hz, which is consistent with our theoretical prediction.