High-performance CFD for Respiratory Droplet Turbulent Dispersion in a Ventilated City Bus

Abstract

This work focuses on the development of a simulation strategy able to quantify risks of airborne virus contagion in many scenarios found in enclosed domains by using high-fidelity fluid dynamics simulation to predict the trajectories and distribution of virus-loaded respiratory droplets over long times. Large-Eddy simulation is used to predict the turbulent flow fields in a city bus for different operating conditions of the Air Conditioning system. The time-averaged velocity distributions and associated turbulent kinetic energy are shown to be drastically dependent on the studied operating conditions. Lagrangian tracking of respiratory droplets is then used over long times on statically converged Eulerian flow fields to investigate their turbulent dispersion depending on the emitter position in the bus. Importance of air conditioning conditions on respiratory droplet trajectories and concentration in the configuration is illustrated indicating that air treatment devices play a crucial role in the mitigation solution of airborne virus propagation.

Keywords:

• Airborne virus propagation
• Large-Eddy simulation
• Lagrangian simulation
• high-performance computing

Acknowledgements

This work was granted access to the HPC resources of GENCI/TGCC (Joliot-Curie supercomputer) on the PRACE fast track allocation project CFDforCOVID dedicated to COVID-19 pandemic studies. This work was also granted access to the HPC resources of CINES under the allocation A0092B12050 made by GENCI.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 Example of a UV air purification system developed by VALEO, https://www.valeo-thermalbus.com/eu_en/Innovation/UV-air-purification