Air circulation effects on airborne particles aboard cruise ships

Virus outbreaks on cruise ships pose significant challenges due to their enclosed environments and high passenger densities. Managing these outbreaks has become even more critical as cruise ships have increased in size and passenger capacity. This study uses numerical simulations to investigate the dispersion of airborne respiratory droplets and aerosols within a passenger cabin on a cruise ship, focusing on the angle of the mechanical ventilation jet's influence. Although previous research primarily focused on larger respiratory droplets that quickly settle, this study emphasizes aerosols under 10 μm that can remain airborne for extended periods. The findings demonstrate that variations in the inflow angle from the ventilation unit can significantly affect aerosol dispersion. The results show that the travel distance of the larger droplets is more effectively restricted at the larger 75° inlet angle. Smaller droplets with a diameter ranging between 1-10 and 10-50 μ m can remain airborne 1.4 m above ground 20% and 40% longer, respectively. These insights underscore the importance of tailored air circulation strategies to reduce transmission risks in confined spaces, such as cruise ship cabins, highlighting the need for optimized ventilation design to manage infectious disease outbreaks.