Abstract
Person-to-person transmission of droplets and droplet nuclei during expiratory activities
constitutes a prerequisite for airborne and droplet-borne infections. This study focuses on the
impact of modelling simplifications on one manikin’s exposure to the other’s expiratory
droplets via breathing. The exhalation airflows are compared and validated by measurement
results of human subjects. The flow field between two manikins are found significantly
influenced by their exhalation airflows. Mono-dispersed droplets with an initial diameter of 10
μm are released from one breathe of a manikin. All droplets are found to become droplet nuclei
before reaching the other manikin. Though the flow field is not quite influenced by the room
macroenvironment, the room air conditions affect the dispersion of droplet nuclei significantly.
Direct exposure of expiratory droplet nuclei are found to be overestimated, when simplifying
the room air condition into isothermal condition, or neglecting the body plume of the manikin.
It will also change the microenvironment completely by simplifying the shape of human grid
in to a robot shape. The trajectories of both the exhalation airflows and droplet nuclei are
significantly different from a detailed shape of human body and mouth.
constitutes a prerequisite for airborne and droplet-borne infections. This study focuses on the
impact of modelling simplifications on one manikin’s exposure to the other’s expiratory
droplets via breathing. The exhalation airflows are compared and validated by measurement
results of human subjects. The flow field between two manikins are found significantly
influenced by their exhalation airflows. Mono-dispersed droplets with an initial diameter of 10
μm are released from one breathe of a manikin. All droplets are found to become droplet nuclei
before reaching the other manikin. Though the flow field is not quite influenced by the room
macroenvironment, the room air conditions affect the dispersion of droplet nuclei significantly.
Direct exposure of expiratory droplet nuclei are found to be overestimated, when simplifying
the room air condition into isothermal condition, or neglecting the body plume of the manikin.
It will also change the microenvironment completely by simplifying the shape of human grid
in to a robot shape. The trajectories of both the exhalation airflows and droplet nuclei are
significantly different from a detailed shape of human body and mouth.
| Original language | English |
|---|---|
| Title of host publication | 14th International Conference on Indoor Air Quality and Climate (INDOOR AIR 2016) |
| Volume | 3 |
| Publisher | International Society of Indoor Air Quality and Climate |
| Publication date | 2016 |
| Pages | 1484-1491 |
| ISBN (Print) | 978-1-5108-3687-7 |
| Publication status | Published - 2016 |
| Event | Indoor Air 2016: The 14th international conference of Indoor Air Quality and Climate - Ghent, Belgium Duration: 3 Jul 2016 → 8 Jul 2016 |
Conference
| Conference | Indoor Air 2016 |
|---|---|
| Country/Territory | Belgium |
| City | Ghent |
| Period | 03/07/2016 → 08/07/2016 |
Keywords
- Airborne infection
- Exhalation airflow
- Manikin
- Micro-environment