Bubble Backflipping

Bubble Backflipping Alireza Hooshanginejad, Cornell University Anuj Baskota, Cornell University Sunghwan Jung, Cornell University DOI: We discover that when bubbles of an intermediate size range (i.e. mm in radius) impact a tilted surface, they exhibit a backward flipping motion. This backflipping behavior is strongly dependent on the angle of the tilted surface. At low angles, the second impact falls behind the first impact. At intermediate angles, the bubble goes backward for a period between the first two impacts, but the second impact falls ahead of the first impact. At large angles, the backflipping stops. We show that an asymmetric circulation around the bouncing bubble yields a lift force that is responsible for the backblipping behavior. See other videos from the 2021 Gallery of Fluid Motion: