Coughing has been confirmed as a significant vector for transmitting respiratory diseases. It can be modelled physically as a turbulent jet to study the dispersion of expiratory droplets. The discrete random walk model for particle tracking is employed to study the effect of turbulence fluctuation on dispersion of particles and/or droplets. The concept of reach probability is proposed to characterise the streamwise spread distance. Our study shows that jet-like cough airflow turbulence prompts the wide spread of particles and expiratory droplets, and that the effect of evaporation on medium droplets (50 μm) is most significant. When turbulence fluctuations are considered for the 100 μm particles, there is a four-fold increase in the dispersion range in the streamwise direction, and a thirteen-fold increase in the transverse direction compared to that without fluctuation. Small particles are found to follow the airflow closely, dispersing in the whole jet region, while only 1% of large particles exceed 2 m in the streamwise direction; nearly 10% of medium particles travel 4.0 m (initial u0 = 10 m/s, mouth diameter D = 2 cm). Droplets evaporate after being exhaled, but fates of small droplets with initial diameter dp0 = 30μm as well as large droplets with dp0 = 100μm are little affected by relative humidity (RH). The 30 μm droplets evaporate in seconds and behave similarly to the 10 μm particles. The spread distance of large droplets is mainly determined by the jet outlet diameter and velocity. In contrast, the medium droplets are found to be very sensitive to RH under humid conditions (RH≥80%).
Building and Environment – Elsevier
Published: Nov 1, 2015
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.
All for just $49/month
Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.
Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.
It’s easy to organize your research with our built-in tools.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera