@Article{fdmp.2025.068093,
AUTHOR = {Chuhan Zhao, Souad Morsli, Laurent Caramelle, Mohammed El Ganaoui},
TITLE = {Ventilation Velocity vs. Airborne Infection Risk: A Combined CFD and Field Study of CO<sub>2</sub> and Viral Aerosols},
JOURNAL = {Fluid Dynamics \& Materials Processing},
VOLUME = {21},
YEAR = {2025},
NUMBER = {8},
PAGES = {2001--2025},
URL = {http://www.techscience.com/fdmp/v21n8/63757},
ISSN = {1555-2578},
ABSTRACT = {Carbon dioxide (CO<sub>2</sub>) is often monitored as a convenient yardstick for indoor air safety, yet its ability to stand in for pathogen-laden aerosols has never been settled. To probe the question, we reproduced an open-plan office at full scale (7.2 m  5.2 m  2.8 m) and introduced a breathing plume that carried 4% CO<sub>2</sub>, together with a polydisperse aerosol spanning 0.5–10 m (1320 particles s<sup>−1</sup>). Inlet air was supplied at 0.7, 1.4, and 2.1 m s<sup>−1</sup>, and the resulting fields were simulated with a Realisable – RANS model coupled to Lagrangian particle tracking. Nine strategically placed probes provided validation; the calibrated solution deviated from the experiment by 58 ppm for CO<sub>2</sub> (8.1% RMSE) and 0.008 m s<sup>−1</sup> for velocity (15.7% RMSE). Despite this agreement, gas and particles behaved in sharply different ways. Room-averaged CO<sub>2</sub> varied by <15%, whereas the aerosol mass rose to almost three-fold the background within slow-moving corner vortices. Sub-micron particles stayed aloft along streamlines, while those 5 m peeled away and settled on nearby surfaces. The divergence shows that neither the CO<sub>2</sub> level nor the mean age of air, taken in isolation, delineates all high-exposure zones. We therefore recommend that ventilation design be informed by a composite diagnosis that couples gas data, size-resolved particle measurements, and rapid CFD appraisal.},
DOI = {10.32604/fdmp.2025.068093}
}