How whitecaps form in the sea
A research group led by ETH Professor Petros Koumoutsakos from the Computational Science & Engineering Laboratory was awarded the 2019 APS/DFD Gallery of Fluid Motion Award for its video on the formation of foam crowns on waves.
The external pageprizecall_made was awarded at the 72nd Annual Meeting of the Division of Fluid Mechanics of the American Physical Society in Seattle (USA) at the end of November. The award went to Professor Petros Koumoutsakos, doctoral student Petr Karnakov and postdoc Sergey Litvinov from the Computational Science & Engineering Laboratory as well as software engineer Jean M. Favre from the Swiss National Supercomputing Centre for the visualization. For their work, the researchers used the supercomputer "Piz Daint" to investigate how foam is formed and what its formation depends on.
The research findings are visualized in the video. It shows how breaking sea waves trap air and produce bubbles that clump together to form foam. According to the scientists, the foam is produced by inhibiting bubble coalescence due to the presence of surfactants and other impurities in the water. In addition, the research group presented a novel volume-of-fluid method that can distinguish between bubble clustering and coalescence.