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Torques on curved atmospheric fibres
Summary
Researchers derived a theoretical model for how planar curved atmospheric fibers settle in quiescent air, finding that fluid-inertia torques can align asymmetric fibers at oblique angles relative to gravity — consistent with recent laboratory observations. The model demonstrates that inertial alignment is a general and important factor governing the atmospheric transport of asymmetric particles such as curved microplastic fibers and ash particles.
Small particles are transported over long distances in the atmosphere, with significant environmental impact. The transport of symmetric particles is well understood, but atmospheric particles, such as curved microplastic fibres or ash particles, are generally asymmetric. This makes the description of their transport properties uncertain. Here, we derive a model for how planar curved fibres settle in quiescent air. The model explains that fluid-inertia torques may align such fibres at oblique angles with gravity as seen in recent laboratory experiments, and shows that inertial alignment is a general and thus important factor for the transport of atmospheric particles.
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