Thin Films Under Action of Surface Acoustic Waves: Experiments, Modeling, and Simulations

This talk focuses on modeling and computations of experiments involving silicon oil films spreading under the action of surface acoustic waves. Specifically, we focus on the films driven by MHz-frequency Rayleigh surface acoustic waves (SAWs) and their association with Eckart streaming: a mass transport mechanism induced by sound or ultrasound wave attenuation within the liquid film. While three different acoustic mechanisms can cause streaming (Stokes drift, acoustic radiation pressure, and Eckart streaming), our particular focus is on Eckart streaming, which becomes increasingly significant for thicker films. Within long-wave approximation, we arrive at a variant of the thin film equation with an additional SAW term used to describe film dynamics. Finally, We discuss the comparison of experimental and computational findings.