Verma, AK and Bhatnagar, A and Mitra, D and Pandit, R (2020) First-passage-time problem for tracers in turbulent flows applied to virus spreading. In: Physical Review Research, 2 (3).
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Abstract
We study the spreading of viruses, such as SARS-CoV-2, by airborne aerosols, via a first-passage-time problem for Lagrangian tracers that are advected by a turbulent flow: By direct numerical simulations of the three-dimensional (3D) incompressible Navier-Stokes equation, we obtain the time tR at which a tracer, initially at the origin of a sphere of radius R, crosses the surface of the sphere for the first time. We obtain the probability distribution function P(R,tR) and show that it displays two qualitatively different behaviors: (a) for Râ‰LI, P(R,tR) has a power-law tail ∼tR-α, with the exponent α=4 and LI the integral scale of the turbulent flow; (b) for LI≲R, the tail of P(R,tR) decays exponentially. We develop models that allow us to obtain these asymptotic behaviors analytically. We show how to use P(R,tR) to develop social-distancing guidelines for the mitigation of the spreading of airborne aerosols with viruses such as SARS-CoV-2. © 2020 authors. Published by the American Physical Society.
| Item Type: | Journal Article |
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| Publication: | Physical Review Research |
| Publisher: | American Physical Society |
| Additional Information: | The copyright for this article belongs to the Author(s). |
| Keywords: | Aerosols; Atmospheric movements; Diseases; Distribution functions; Tracers; Turbulent flow; Viruses, Asymptotic behaviors; First passage time problem; Incompressible Navier Stokes equations; Lagrangian; Power-law tail; Sphere of radius R; Threedimensional (3-d); Virus spreading, Navier Stokes equations |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 13 Jan 2023 06:36 |
| Last Modified: | 13 Jan 2023 06:36 |
| URI: | https://eprints.iisc.ac.in/id/eprint/79102 |
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