Evaluation of airborne disease infection risks in an airliner cabin using the Lagrangian-based Wells-Riley approach

Abstract

a b s t r a c tAn urgent demand of assessing passengers' exposure risks in airliner cabins was raised as commercial airliners are one of the major media that carrying and transmitting infectious disease worldwide. In this study, simulations were conducted using a Boeing 737 cabin model to study the transport characteristics of airborne droplets and the associated infection risks of passengers. The numerical results of the airflow field were firstly compared against the experimental data in the literature to validate the reliability of the simulations. Airborne droplets were assumed to be released by passengers through coughing and their transport characteristics were modelled using the Lagrangian approach. Numerical results found that the particle travel distance was very sensitive to the release locations, and the impact was more significant along the longitudinal and horizontal directions. Particles released by passengers sitting next to the windows could travel much further than the others. A quantifiable approach was then applied to assess the individual infection risks of passengers. The key particle transport information such as the particle residence time yielded from the Lagrangian tracking process was extracted and integrated into the Wells-Riley equation to estimate the risks of infection. Compared to the Eulerian-based approach, the Lagrangian-based approach presented in this study is more robust as it addresses both the particle concentration and particle residence time in the breathing zone of every individual passenger.

Modelling of evaporation of cough droplets in inhomogeneous humidity fields using the multi-component Eulerian-Lagrangian approach

“…9 (b), the gravitational settlement of droplets became more significant. Particularly, when the mass flow rate of droplets increased to 1000 mg, the droplets presented a remarkably changed distribution pattern, which will certainly result in different risk assessments if the assessments were based on droplet trajectories [27]. The time-dependent sizes of the representative droplets (12-μm and 112-μm) are shown in Fig.…”

Evaluating the commercial airliner cabin environment with different air distribution systems

“…In addition to experimental studies, computational fluid dynamics (CFD) has been used extensively in the cabin environment, to design and optimize air supply, [24][25][26][27][28] predict transient particle transport, [29][30][31] evaluate airborne infectious diseases risks, [32][33][34] and identify source location. 35,36 For example, Qian et al 32 calculated the distributions of the air velocity, air temperature, and CO 2 concentration in a section of a Boeing 767 aircraft cabin with a mixing ventilation system.…”

“…In addition to experimental studies, computational fluid dynamics (CFD) has been used extensively in the cabin environment, to design and optimize air supply, predict transient particle transport, evaluate airborne infectious diseases risks, and identify source location . For example, Qian et al combined the CFD simulations and Wells‐Riley equation to evaluate the spatial distribution of infection risk of SARS transmission in a hospital ward.…”

An innovative personalized displacement ventilation system for airliner cabins

“…Many previous studies have demonstrated that it is difficult to precisely predict the airflow, temperature, and contaminant concentration distribution in real or full-scale-mockup aircraft cabins [ 11,[22][23][24]. Specifically, it is very challenging to precisely measure the boundary conditions due to the complex geometry and limited space in the cabin.…”