Did you know that on average, a healthy person sneezes far more than they cough? Sneezing plays an important role in cases of coronavirus transmission by asymptomatic carriers. Existing models for studying sneezes tend to treat the head as rigid – without any motion or individual variations that can have an effect on the predicted dynamics and spatial region covered by the sneeze. By including head motion, Busco et al. developed a more realistic sneezing model for studying complex coronavirus transmission scenarios.

A combination of experimental and computational techniques allowed the group to create their dynamic model. They captured the flow characteristic of sneezes induced in a healthy adult to incorporate human factors – specifically, head motion and changes in pressure – while treating the sneeze as a momentum source.

These extra considerations allowed the authors to reanalyze the cloud spread of a sneeze, which turned out to cover at least twice as much space compared to that predicted traditionally. The authors also used the technique to investigate the effects of humidity, temperature and air pollution.

“Is it safer to sneeze in a hot, humid and polluted city, or in a cold, dry and clean air suburb?” said author Giacomo Busco. “Our study can answer this question.”

By customizing computational conditions to include things like air circulation, the model can be adapted to specific settings, such as a particular office or factory. The group is currently using their model to optimize some of their university classroom setups in anticipation of reopening, in addition to aiding the rail transport industry to manage seating.

Source: “Sneezing and asymptomatic virus transmission,” by Giacomo Busco, Se Ro Yang, Joseph Seo, and Yassin A. Hassan, Physics of Fluids (2020). The article can be accessed at https://doi.org/10.1063/5.0019090.