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arXiv · 2101.05662

A numerical cough machine

Cesar Pairetti·Raphaël Villiers·Stéphane Zaleski
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Abstract

We introduce a simplified model of physiological coughing or sneezing, in the form of a thin liquid layer subject to a rapid (30 m/s) air stream. The setup is simulated using the Volume-Of-Fluid method with octree mesh adaptation, the latter allowing grid sizes small enough to capture the Kolmogorov length scale. The results confirm the trend to an intermediate distribution between a Log-Normal and a Pareto distribution $P(d) \propto d^{-3.3}$ for the distribution of droplet sizes in agreement with a previous re-analysis of experimental results by one of the authors. The mechanism of atomisation does not differ qualitatively from the multiphase mixing layer experiments and simulations. No mechanism for a bimodal distribution, also sometimes observed, is evidenced in these simulations.

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Cesar Pairetti, Raphaël Villiers, Stéphane Zaleski. 2021-01-14. A numerical cough machine. https://arxiv.org/abs/2101.05662

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