Schlieren photography as a great tool to study wave diffraction at the end of a plate

Abstract

A study by means of the Schlieren technique for visualization of ultrasonic beams, has revealed that when leaky Rayleigh waves, propagating along the horizontal edge of a thick, fluid loaded solid plate, are scattered at the extremity of the plate, they travel around the corner and start leaking into the liquid along the Rayleigh angle measured from the normal to the vertical edge of the plate. Furthermore the study reveals that leaky Rayleigh waves are stimulated by the border of an incident ultrasonic bounded beam, more than by the interior of the beam. Comparison with an earlier work shows that the characteristics of the scattering of leaky Rayleigh waves at the edge of the plate is very different from that of Scholte - Stoneley waves.