jsc2022e072959 (9/16/2022) --- Coarse hydrophobic sand is mixed for 25 seconds with water and air. Researchers observe a decent amount of agglomerates (air bubbles) covered by hydrophobic sand particles flowing in the water body. There are also free sand particles floating around. Catastrophic Post-Wildfire Mudflows studies the formation and stability of this bubble-sand structure in microgravity. A better understanding of these phenomena could improve the understanding, modeling, and predicting of mudflows and support development of innovative solutions to prevent catastrophic post-fire events. Image courtesy of the UCSD Geo-Micromechanics Research Group.

jsc2022e072960 (9/16/2022) --- Front view of flow of mixture of hydrophobic medium sand particles, water, and air. After mixing hydrophobic medium sand particles with water and air, researchers flow the mixture through the pipe. Both agglomerates and excess free sand particles are visible. Researchers also observe the segregation phenomenon during the flow of this particular mixture. Agglomerates do not occupy the pipe uniformly and do not always flow at the same speed. Catastrophic Post-Wildfire Mudflows studies the formation and stability of this bubble-sand structure in microgravity. A better understanding of these phenomena could improve the understanding, modeling, and predicting of mudflows and support development of innovative solutions to prevent catastrophic post-fire events. Image courtesy of the UCSD Geo-Micromechanics Research Group.