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Numerical model for cough-generated droplet dispersion on moving escalator with multiple passengers
Ayato Takii1, Masashi Yamakawa1, Atsuhide Kitagawa1
1Department of Mechanical Engineering, Kyoto Institute of Technology, Kyoto, Japan.
Indoor Air
|November 28, 2022
Summary
Ascending escalators pose a higher risk for virus-laden droplet transmission than descending ones. Maintaining social distance significantly reduces the chance of viral droplet adhesion.
Area of Science:
- Fluid dynamics
- Aerosol science
- Public health
Background:
- Public transportation systems like subways facilitate close contact among individuals.
- Understanding airborne droplet transmission is crucial for preventing disease spread, especially in crowded environments.
Purpose of the Study:
- To numerically simulate virus-laden droplet motion in an escalator environment.
- To assess the risk of airborne transmission between passengers on escalators.
Main Methods:
- Developed a detailed geometric model of an escalator with passengers.
- Applied the moving computational domain and moving-grid finite-volume methods for airflow simulation.
- Computed droplet dispersion using droplet motion equations and considering cough parameters, size distribution, and evaporation.
Main Results:
- Identified higher exposure risk to virus-laden droplets on ascending escalators compared to descending ones.
- Demonstrated that droplet adhesion risk decreases with increasing distance from an infected individual.
- Simulations resolved detailed droplet motion influenced by escalator-specific airflow.
Conclusions:
- Ascending escalators present a greater risk for airborne virus transmission.
- Social distancing is a critical measure to mitigate viral droplet exposure on escalators.
- The study highlights the importance of airflow dynamics in understanding droplet spread in public transit.
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