BOSS

Building Occupants Signal Synthesis

The paper has been published in the Journal of Occupational and Environmental Hygiene (here)

A cough jet can travel beyond the breathing zone of the source person, and thus, infectious viral- and bacterial-laden particles can be transported from the source person to others in close proximity. To reduce the interpersonal transmission of coughed particles, the objective of this study was to analytically and experimentally investigate the performance of downward plane jets with various discharge velocities. Chamber measurements were conducted to examine the interaction between a transient cough jet (discharge velocities of 12 m/sec and 16 m/sec) and a steady downward plane jet (discharge velocities from 1.0–8.5 m/sec) with respect to the transport of and human exposure to coughed particles. 

Experimental setup:

Particle generator

 

Supply air system (POV air curtain)

 

Two thermal dummies facing each other

 

A trajectory model was developed based on the ratio of the two momentums of a cough jet and a downward jet and was validated using the experimental data. In addition, the predicted trajectory of the cough jet agreed well with the results from smoke visualization experiments. This model can be used to guide the design of downward plane jet systems for protection of occupants from coughed particles.

 

Coughed particles transmission (smoke visualization)