CNLD seminar with Likun Zhang

Abstract: Ripples on water interacting with obstacles are common in everyday life. Surface tension forms a curved meniscus a few millimeters high at the interfaces between liquid, solid ,and air. Unlike simpler shapes like droplets or bubbles, this meniscus has varying curvature that significantly alters wave propagation and scattering, effects not well explained by classical theory or past experiments. We measured wave transmission past a surface-piercing barrier, focusing on the meniscus effects. By changing the obstacle’s surface coating, we adjusted the meniscus shape and saw major differences in ripple propagation. High-precision acoustic measurements of ripple amplitudes show that this small feature can enhance or suppress transmission depending on its shape and wave frequency. Combining experiments and modeling, we reveal how meniscus deformations affect wave behavior. These findings highlight how small-scale surface features can impact fluid dynamics on larger scales, with applications in microfluidics, wave control, and soft robotics.