SELF-REFRACTION OF IMPULSE AND QUASI-STATIONARY ACOUSTIC BEAMS CONTAINING SHOCK FRONTS IN A NEWTONIAN FLUID

Abstract

The self-refraction of some beams in a Newtonian fluid is theoretically studied. A single pulse that takes the shape of an isosceles triangle at a transducer and a solitary shock wave are considered as examples. The novelty lies in the consideration of a quasi stationary shock wave (with positive or negative pressure) and negative triangular pulses. We conclude that waveforms with negative excess pressure undergo self-focusing, in contrast to those with positive excess pressure. The difference in self-refraction of quasi stationary and impulse beams is revealed by means of numerical modeling.