CBE Seminar: Fluid dynamics of speech: Mechanisms underlying COVID-19 transmission
- Thursday, February 4, 2021 from 4:10pm to 5:00pm
Dr. Howard Stone is the Donald R. Dixon '69 and Elizabeth W. Dixon Professor in Mechanical and Aerospace Engineering at Princeton University, where he works within the broad space of complex fluids. His seminar will focus on transmission of SARS-CoV-2 via speech.
Abstract: Speech is a potent route for viral transmission in the COVID-19 pandemic. Informed mitigation strategies are difficult to develop since the relationship of speech to the exhaled flow has not been documented, nor has the aerosolization mechanism in the oral cavity been visualized. We document the spatio-temporal structure of the expelled air flow and detail how drops form using high-speed imaging. Specifically, phonetic characteristics of plosive sounds like `P' lead to enhanced directed transport, including jet-like flows that entrain the surrounding air. The transport features are demonstrated using order-of-magnitudes estimates, numerical simulations, and laboratory experiments. Different configurations of speakers can then be studied to understand risk of infection in casual conversations. Also, we show with high-speed imaging how phonation of common stop-consonants form and extend viscoelastic salivary filaments in a few milliseconds as moist lips open or when the tongue separates from the teeth, which produces centimeter-scale thin filaments, tens of microns in diameter, that break into speech droplets. We believe that this work will inform thinking about the role of ventilation, aerosol transport in disease transmission for humans and other animals and yield a better understanding of “aerophonetics.”
Host and moderator: Dr. Connie Chang
Contact CBE for access to this seminar