Abstract
The dispersion of cough-generated aerosols in enclosed healthcare environments poses a significant risk of airborne transmission, necessitating effective ventilation strategies to safeguard patients and healthcare staff. Conventional ceiling-mounted ventilation systems often fail to rapidly remove particles from the breathing zone, motivating the need for localized airflow enhancement. This study investigates the combined effect of pedestal fan-assisted ventilation and patient coughing inclination on aerosol transport, droplet clearance, and infection risk within a dental room. A transient computational fluid dynamics (CFD) model was developed to simulate the evolution of cough-generated droplets under varying patient inclinations and different fan speeds. The results reveal that particle transport is governed by the interplay of cough jet momentum, aerodynamic drag, turbulent dispersion, and gravitational settling. At 0°, droplets remain suspended, resulting in the highest infection risk, exceeding 75% under low airflow conditions. With a 30° inclination, the risk decreases to 64%, while at 45° it further reduces to 42% under low airflow and to 26% under high airflow, confirming the optimal alignment of cough momentum with ventilation streamlines. The droplet number fraction also shows the greatest reduction at 45°, decreasing by 21.5% under low airflow and by 28.4% under high airflow compared to 0°. Larger droplets consistently settle due to gravity, whereas smaller aerosols remain entrained until cleared by the outlet-directed airflow. The findings demonstrate that optimizing patient inclination, particularly at 45°, in conjunction with higher fan speeds, significantly enhances particle clearance and reduces infection risk. This approach can be effectively applied in dental clinics and similar indoor settings, where quick aerosol control is essential to reduce the risk of cross-infections. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-026-00973-5.