The exploitation of the subharmonic pressure waves from pulsating gas bubbles in an acoustic field in liquids

Abstract

Under certain conditions, subharmonic oscillation at one-half the frequency of the excitation may be generated by gas bubbles driven by an alternating pressure. An extremely simple acoustical method is suggested for determining the viscosity of highly viscous liquids. The method involves the measurement of the threshold pressure of the onset of subharmonic oscillation at a given driving acoustic frequency.