Visualization and control of acoustic levitation using model-based Schlieren imaging

This seminar presents a method for visualizing the ultrasonic acoustic field under which particles can be levitated in the air and their position can be controlled. Acoustic levitation leverages the nonlinear behavior of compressible fluids, where sinusoidal excitation creates spatially fixed static pressure and local potential wells. Particles can be suspended in mid-air within these wells without physical contact. This research aims to improve the understanding of how to move these potential wells in a controlled manner. To better control and shape the acoustic field, it is essential to understand its three-dimensional distribution of pressure. It appears that state-of-the-art numerical modeling cannot account for key factors at these high frequencies, including viscous effects, streaming, reflections, and unmodeled nonlinear behavior.