Investigation of interaction of surface acoustic waves with liquid in the ultrasonic range

Abstract

In the paper experimental results of investigation of interaction between transversal surface acoustic waves (TSAW, Rayleigh waves), longitudinal surface acoustic waves (LSAW) and liquid in the ultrasonic range (2 MHz) are presented. It was determined, that TSAW amplitude is particularly sensitive to contact of solid body and liquid (drops, thin layer, thick layer) and rapidly decreases with increase of liquid layer thickness. When the thickness of the liquid layer h < Λ (Λ – length of acoustic wave in liquid), TSAW amplitude decreases in interferential manner with increase of propagation distance d. When h >> Λ, the TSAW amplitude level stabilizes and is determined by mechanical surface dampening, which depends on the acoustic impedance of liquid.
Experiment results show that when TSAW propagate along the surface covered by liquid layer, intense bulk longitudinal waves are excited in it and for this reason TSAW are attenuated. Meanwhile, liquid influence on the attenuation of LSAW waves is marginal.
It was shown, that investigation of surface acoustic waves in the ultrasonic range allows creation of physical models of the Earth seismic phenomena, also could be useful to investigate tsunami formation and its properties.