Airborne and aerosol pathogen transmission modeling of respiratory events in buildings: An overview of computational fluid dynamics

Yahya Sheikhnejad; Reihaneh Aghamolaei; Marzieh Fallahpour; Hamid Motamedi; Mohammad Moshfeghi; Parham A Mirzaei; Hadi Bordbar

doi:10.1016/j.scs.2022.103704

Airborne and aerosol pathogen transmission modeling of respiratory events in buildings: An overview of computational fluid dynamics

Sustain Cities Soc. 2022 Apr:79:103704. doi: 10.1016/j.scs.2022.103704. Epub 2022 Jan 19.

Authors

Yahya Sheikhnejad^{1

2}, Reihaneh Aghamolaei³, Marzieh Fallahpour³, Hamid Motamedi⁴, Mohammad Moshfeghi⁵, Parham A Mirzaei⁶, Hadi Bordbar⁷

Affiliations

¹ Centre for Mechanical Technology and Automation, Department of Mechanical Engineering, Universidade de Aveiro, Aveiro 3810-193, Portugal.
² PICadvanced SA, Creative Science Park, Via do Conhecimento, Ed. Central, Ílhavo 3830-352, Portugal.
³ School of Mechanical and Manufacturing Engineering, Faculty of Engineering and Computing, Dublin City University, Dublin 9, Whitehall, Ireland.
⁴ Department of Mechanical Engineering, Tarbiat Modares University, Iran.
⁵ Department of Mechanical Engineering, Sogang University, Seoul, South Korea.
⁶ Architecture & Built Environment Department, University of Nottingham, University Park, Nottingham, UK.
⁷ School of Engineering, Aalto University, Finland.

Abstract

Pathogen droplets released from respiratory events are the primary means of dispersion and transmission of the recent pandemic of COVID-19. Computational fluid dynamics (CFD) has been widely employed as a fast, reliable, and inexpensive technique to support decision-making and to envisage mitigatory protocols. Nonetheless, the airborne pathogen droplet CFD modeling encounters limitations due to the oversimplification of involved physics and the intensive computational demand. Moreover, uncertainties in the collected clinical data required to simulate airborne and aerosol transport such as droplets' initial velocities, tempo-spatial profiles, release angle, and size distributions are broadly reported in the literature. There is a noticeable inconsistency around these collected data amongst many reported studies. This study aims to review the capabilities and limitations associated with CFD modeling. Setting the CFD models needs experimental data of respiratory flows such as velocity, particle size, and number distribution. Therefore, this paper briefly reviews the experimental techniques used to measure the characteristics of airborne pathogen droplet transmissions together with their limitations and reported uncertainties. The relevant clinical data related to pathogen transmission needed for postprocessing of CFD data and translating them to safety measures are also reviewed. Eventually, the uncertainty and inconsistency of the existing clinical data available for airborne pathogen CFD analysis are scurtinized to pave a pathway toward future studies ensuing these identified gaps and limitations.

Keywords: Aerosol; Airborne pathogen; Buildings; CFD; COVID19; Droplet release; Respiratory events.

Publication types

Review