Experimental study of liquids interface oscillatory dynamics in rotating slot gap

Abstract

The shape of the interface between two liquids in a non-uniformly rotating slotted gap with a circular boundary is experimentally investigated. The liquids have different densities and a high viscosity contrast. We have found that the axisymmetric interface becomes unstable with an increase in the amplitude of the modulation of the rotation rate, a quasi-stationary azimuthally periodic relief excites in a threshold manner. The shape of the interface is studied by photoregistration as a function of the rotation rate, amplitude and frequency of the rotation rate modulation. The relative volume of a viscous liquid and the properties of liquids (viscosity contrast, relative density, coefficient of interfacial tension) vary. We found that the relief develops at the interface regardless of where the more viscous liquid is located, outside or inside.