Session: 11-45-01: Applications of Computational Heat Transfer

Paper Number: 94143

94143 - Vapour Cough Visualization for COVID-19 – Computational Modelling Approach 

Recently, New Zealand and many countries and organizations gained heightened awareness of indoor air quality (IAQ) issues, and increased investment, according to the World Health Organization (WHO) guidelines, to improve their IAQ and reduce air pollution in commercial and residential buildings. Additionally, some countries have introduced new standards for indoor environments, such as the New Zealand “healthy homes” standard. At the same time, the COVID-19 pandemic forced many people to spend much more time in indoor spaces, due to stay-at-home, or lockdown orders by governments. This increased attention on other aspects of indoor environmental quality, such as occupants’ satisfaction with thermal comfort parameters presents an additional parameter for researchers and in the development of standards.

From a medical point of view, infectious respiratory diseases, such as influenza or COVID-19, are transmitted by airborne droplets. Large droplets containing the pathogen, exhaled from infected occupants and inhaled by the uninfected occupants, were numerically investigated based on outbreak SARS in 2003.  Mathematical and computational models were presented using a virtual thermal mannequin to investigate the airborne spread of the expiratory droplet. Consequently, the last 20 years have provided some important insights into efficient ventilation technologies to achieve the combined goal of a comfortable indoor climate for occupants and reduced risk of cross-infection and contaminant spread in the air in a closed indoor environment. However, the CFD simulation of the after-effect of using new technologies such as HEPA filtration combined with Ultraviolet Germicidal Irradiation (UVGI) light in a device has not been adequately investigated. In this work, we assess a Polyester Filter and UV light (PFUV) dehumidifier device performance in an office with two occupants (one infected and the other one uninfected with a disease with airborne transmission, such as COVID-19) using the CFD approach.

The aim of this study is to investigate two positions for locating the PFUV dehumidifier in an office with a scenario in which one person is exhaling air carrying the infection, and the other occupant must inhale and exhale from the shared air. The CFD model, constructed with ANSYS® 2021 Fluent using the discrete phase model (DPM) for the particle treatment will be validated with the experimental data to generate a model within ANSYS to predict future design and device placement. In addition to that, thermal comfort analysis will be investigated using IAQ and comfort kit with tripod (Testo 400) and Testo 410-2 NTC. 

Keywords: infectious respiratory diseases, Ultraviolet Germicidal Irradiation (UVGI), dehumidifier, CFD modelling, discrete phase model (DPM)

Presenting Author: Mohammad Al-Rawi Centre for Engineering and Industrial Design - Waikato Institute of Technology

Presenting Author Biography: Dr. Mohammad Al-Rawi is an expert in Computational Fluid Dynamics (CFD) and Finite Element (FE) modelling. He used CFD and FE modelling to develop a non-invasive method for detecting cardiovascular diseases and analysing thermal comfort for residential housing in New Zealand. He is also investigating sports engineering applications such as helmet design and fitness education analysis.

Authors:

Mohammad Al-Rawi Centre for Engineering and Industrial Design - Waikato Institute of Technology
Ahmed Al-Jumaily Institute of Biomedical Technologies- Auckland University of Technology