Numerical modeling of cough airflow: Establishment of spatial–temporal experimental dataset and CFD simulation method

Numerical modeling of sneeze airflow and its validation with an experimental dataset

“…In the case of a male, the sneeze airflow reached 0.58 m for method 1 (Figure 8A) and 0.62 m for method 2 (Figure 8B) at 0.5 s after sneezing, whereas in the case of a female, the airflow reached 0.55 m for method 1 (Figure 8C) and 0.56 m for method 2 (Figure 8D). These results were similar to the cough airflow because the stretching distance of the coughing airflow ranged from 0.55 to 0.63 m after the same time duration 10 …”

“…The total volume of the cough airflow was measured by Zhu et al, 29 and the results averaged 1.4 L in the range of 0.8-2.2 L. Gupta et al measured the airflow volume of respiratory activities using a spirometer, and the average exhaled airflow of cough was 1.2 L. 11,12 In previous study, the total expiratory airflow of coughing was determined by a combination of experimental and numerical analysis, and the results of the total exhaled cough airflow were in the range of 0.93-1.23 L for males and 0.90-1.15 L for females. 10,24,38,39 The F I G U R E 9 Comparison of velocity magnitude variation at the criterion velocity point (x * , y * , z * ) = (2.5, 0, 0) of the sneeze airflow according to each numerical method and experimental results…”

Effects of upper respiratory tract anatomy and head movement on the buoyant flow and particle dispersion generated in a violent expiratory event

“…Non-intrusive measurements of the velocities of the expelled droplets during a cough carried out with Particle Image Velocimetry are reported by Chao et al (2009) , VanSciver et al (2011) , Kwon et al (2012) who measured maximum velocities for coughs between 10 m/s and 15 m/s. More recently Oh et al (2022) suggested values of about 20 m/s.…”

“…The amount of existing literature on the subject is growing fast. However, most of these studies ( Abkarian et al, 2020 ; Diwan et al, 2020 ; Fabregat, Gisbert, Vernet, Ferré, et al, 2021 ; Ho, 2021 ; Lavrinenko et al, 2022 ; Li et al, 2022 ; Oh et al, 2022 ; Trivedi et al, 2021 ; Wang et al, 2021 ) consider pipe-like idealized anatomy without head rotation. In this introduction we have selected the most relevant references related to the aspects discussed in this paper concerning the effects of buoyancy, upper respiratory tract geometry and head movement on the flow generated in a violent expiratory episode.…”

“…The number of studies reporting numerical simulations of violent expiratory events and dispersion of pathogen-laden aerosols has also increased significantly since the beginning of the SARS-CoV-2 pandemic. Most of the research has been performed so far using the numerical solution of the unsteady version of the Reynolds-averaged Navier-Stokes equations (URANS) ( Dbouk & Drikakis, 2020 ; Gupta et al, 2011 ; Ho, 2021 ; Lavrinenko et al, 2022 ; Oh et al, 2022 ; Thatiparti et al, 2017 ; Yang et al, 2018 ; Zhang et al, 2021 ). More computationally expensive Large-Eddy Simulations (LES) ( Abkarian et al, 2020 ; Fontes et al, 2020 ; Foster & Kinzel, 2021 ; Liu et al, 2021 ; Pendar & Páscoa, 2020 ; Trivedi et al, 2021 ; Wang et al, 2021 ) and Direct Numerical Simulations (DNS) ( Diwan et al, 2020 ; Fabregat, Gisbert, Vernet, Ferré, et al, 2021 ; Li et al, 2022 ) have also been reported.…”