Experimental study of shear waves produced in the vicinity of the wall surface by use of pressure-oscillation

Abstract

We observed 2D flow birefringence profile near a vertical flat walls of an upside-down air tight quartz cell filled with CTAB/NaSal aqueous solution. When a tiny bubble is placed inside the top wall of the cell, an oscillating flow can be generated by pressing a rubber film at the bottom of the cell by a sinusoidal vibrating piston whose vibrating amplitude, frequency and center positon of the cell can be tuned precisely. As the bubble is getting contracting and expanding alternately, shear waves were observed clearly, which was propagated from the vertical wall using the 2D high speed polarization camera. In this study, a correlation of the propagated waves and propagation speed of the shear waves were studied and discussed experimentally.