Back to Search
Start Over
The spreading of viruses by airborne aerosols: lessons from a first-passage-time problem for tracers in turbulent flows
- Source :
- Phys. Rev. Research 2, 033239 (2020)
- Publication Year :
- 2020
-
Abstract
- We study the spreading of viruses, such as SARS-CoV-2, by airborne aerosols, via a new 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 $t_R$ at which a tracer, initially at the origin of a sphere of radius $R$, crosses the surface of the sphere \textit{for the first time}. We obtain the probability distribution function $\mathcal{P}(R,t_R)$ and show that it displays two qualitatively different behaviors: (a) for $R \ll L_{\rm I}$, $\mathcal{P}(R,t_R)$ has a power-law tail $\sim t_R^{-\alpha}$, with the exponent $\alpha = 4$ and $L_{\rm I}$ the integral scale of the turbulent flow; (b) for $l_{\rm I} \lesssim R $, the tail of $\mathcal{P}(R,t_R)$ decays exponentially. We develop models that allow us to obtain these asymptotic behaviors analytically. We show how to use $\mathcal{P}(R,t_R)$ to develop social-distancing guidelines for the mitigation of the spreading of airborne aerosols with viruses such as SARS-CoV-2.
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. Research 2, 033239 (2020)
- Publication Type :
- Report
- Accession number :
- edsarx.2001.01260
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevResearch.2.033239