Transmission of COVID-19 virus by cough-induced particles in an airliner cabin section

Abstract

With airborne transmissions found as one of the major transmission routes of SARS-CoV-2, its transmission in airliner cabin environments drew special attention due to high number of imported cases and in-cabin transmissions. This study numerically investigated the transmission of COVID-19 by cough-induced particles in a cabin section of Boeing 737 model. One passenger was coughing in each case, while cough particles with measured size distributions were released during coughs and were tracked using the Lagrangian framework. Outcomes revealed that cough flow released by passengers could develop rapidly into a strong turbulent cough jet, breaking up the local airflow field. The released cough particles were largely dominated by the cough jet within 5 s, especially the first 1.5 s. Deposition of particles under 100 µm were relatively delayed when released from a window-seat location. Small particles (under 50 µm) released by a window-seat passenger were more likely to spread widely in the studied cabin section, which could lead to the highest exposure risks to nearby passengers. Also, due to ventilation design and seating arrangement, cough particles released by the middle-seat passenger were found easily trapped in his/her own local environment. Cough particles released from aisle-seat passengers had the least exposure risk to adjacent passengers.

Airplane cabin mixing ventilation with time‐periodic supply: Contaminant mass fluxes and ventilation efficiency

“…Many experimental and computational fluid dynamics (CFD) papers 9–32 can be found in the literature in which the MV flow in different airplane cabin configurations (e.g., single‐aisle as the B737‐200, A320, and MD‐82, or twin‐aisle as the B767‐300 or A380) was investigated and characterized in terms of its mean and instantaneous flow patterns, distributions of velocity, turbulence, temperature, relative humidity, pressure, and vorticity. The ventilation performance regarding the distribution of (gaseous) contaminants, 11,13,15,17,28,29,32,33–37 droplet and aerosol deposition/dispersion, 15,32,38–45 age of air, 13,27,46,47 thermal comfort (predicted mean vote, predicted percentage dissatisfied) 47–49 and heat 27,48,50 or contaminant 13,35 removal was also reported.…”

“…The ventilation performance regarding the distribution of (gaseous) contaminants, 11,13,15,17,28,29,32,[33][34][35][36][37] droplet and aerosol deposition/ dispersion, 15,32,[38][39][40][41][42][43][44][45] age of air, 13,27,46,47 thermal comfort (predicted mean vote, predicted percentage dissatisfied) [47][48][49] and heat 27,48,50 or contaminant 13,35 removal was also reported.…”

“…A uniform temperature distribution, although it enhances thermal comfort, causes the theoretical upper limit of the heat removal efficiency (HRE) 48 to be limited to 0.5. Furthermore, stagnant zones may be present giving rise to contaminant/heat lock up 13,25,27,36,45,57 and the high-momentum supply air may cause thermal discomfort. 48,49,58 Some studies 36,37,40 pointed out that an improved air quality may be obtained by increasing the ventilation flow rate, though at the expense of increased energy use.…”

Numerical Simulation of the Novel Coronavirus Spread in Commercial Aircraft Cabin

“…There are more than two billion people traveling by air every year [2]. The microenvironment in the commercial aircraft cabin is enclosed, which provides a good place for the virus to spread among passengers [3,4]. Long-distance air travel makes the virus spread broadly and rapidly.…”

“…The other is to treat solid particles or droplets as a discrete phase material and use the Lagrangian's method to calculate the motion characteristics of each particle [14][15][16]. Some in-cabin studies use the discretization method to obtain the trajectory of virus particles [4,17,18]. In addition, Sandro et al replaced respiratory pathogens with smoke particles and concluded that 60% of the particles sink to the surfaces of the cabin due to gravity during the propagation process [19].…”