The physical and chemical effects of ultrasound

Abstract

Ultrasound refers to sound waves above the human hearing range. The physical effects of ultrasound include the turbulence associated with cavitational bubble collapse, microjetting, and the streaming movement of cavitational microbubbles to the pressure antinodes of a standing wave field. These physical effects are strongest near to fluid/solid and fluid/fluid boundaries, which mean that ultrasound is extremely effective in enhancing heat and mass transfer within such boundary layers. Chemical effects arise from free radical production during transient cavitational collapse of bubbles.