Temperature Effects on the Propagation of Transient Ultrasonic Waves in Viscous Fluids

Abstract

The purpose of the present work is to study the propagation phenomenon of transient ultrasonic waves in viscous fluids submitted to temperature variations. Laplace transform is used in order to obtain a solution to the propagation equation of acoustic waves in viscous fluids. This solution is expressed under the form of a convolution product between the pressure at the output of the transmitting transducer and a function, depending on time and position, called the impulse response of the propagation filter. This impulse response depends upon the propagation medium viscosity which varies with temperature. It is considered that the volume viscosity coefficient is governed by a law similar to Andrade's formulae; this assumption is validated by experimental results with a quite good accuracy.