When solids flow like liquids they can make sand dunes sing, and they can also result in a potentially deadly avalanche. Cambridge researchers are studying the physics behind both of these phenomena, which could have applications in industries such as pharmaceuticals, oil and gas.
As grains of sand slide down the side of certain dunes, they create vibrations that can be heard for miles around. The sand avalanches trigger the dune’s natural resonance, but only when conditions are just right. It can’t be too humid, and the grains of sand need to be just the right size and contain silica. Only then will an avalanche cause the dunes to start singing.
Dr Nathalie Vriend, Department of Applied Mathematics and Theoretical Physics, is a specialist in granular flows, and her research focuses both on sand dunes and on avalanches, and how to quantify their behaviour, which can have practical applications in industries including pharmaceuticals, oil and gas.
Image credit: The District