Numerical study on bed-side curtains and ventilation arrangement for mitigating COVID-19 risks in a shipboard ward with heat sources

Abstract

Ward-acquired infections (WAIs) has become a critical concern, particularly for ships with limited resources. An assessment approach combining validated computational fluid dynamics and the novel Wells-Riley assessment method is proposed to evaluate risks in a shipboard ward. Subsequently, the effects of ventilation, bed-side curtains, and non-adiabatic boundaries on substantial aerosol dispersion are analysed, including X/Y directional walkways (activity zones). Results show that patients with severe symptoms can be prioritized for the exhaust zone rather than the supply zone, and the maximum reduction in suspended particles can differ up to 3-folds. Bed-side curtains can decrease the average risk by −26 % and −48 %/−32 %, respectively, for X/Y directional walkways. Moreover, the average risk increases by approximately +21 % and +14 %/+11 % for X/Y directional walkways under a low air change rate (ACH) of 6 h−1. Considering the non-adiabatic boundary, the average risk reduction is approximately −6.2 % for winter and −7.0 % for summer. It supports that bed-side curtains and a recommended ACH of 12 h−1 are effective in reducing risk. The heat transfer through walls has a marginal effect on risks. Overall, this study provides a framework for predicting and analysing spatial-temporal exposure risks. Better strategies can be developed for protecting medical staff from WAIs.