How Turbulent Jets Can Disperse Virus Clouds in Poorly Ventilated Spaces

TL;DR

This paper demonstrates that fan-driven turbulent jets can effectively disperse virus clouds in poorly ventilated indoor spaces, reducing peak concentrations and potentially lowering airborne COVID-19 transmission risk.

Contribution

It introduces a simple turbulent jet system designed to minimize contaminant peaks in enclosed spaces, using Reynolds-average and similarity methods for analysis.

Findings

Turbulent jets significantly reduce peak virus cloud concentrations.

Effectiveness is higher in small, low-occupancy spaces like restrooms.

Turbulent mixing requires some ventilation to be effective.

Abstract

We show that enhanced turbulent mixing can be used to mitigate airborne COVID-19 transmission by dispersing virus-laden clouds in enclosed, poorly ventilated spaces. A simple system of fan-driven turbulent jets is designed so as to minimize peak concentrations of passive contaminants on time scales short compared to the room ventilation time. Standard Reynolds-average and similarity methods are used, and combinations of circular and radial wall jets are considered. The turbulent diffusivity and contaminant mixing time are calculated. Results indicate that this approach can significantly reduce peak virus cloud concentrations, especially in small spaces with low occupancy, such as restrooms. Turbulent mixing is, of course, ineffective in the absence of ventilation.