Real-time particle tracking tests virus mitigation strategies
Real-time particle tracking tests virus mitigation strategies lead image
Now two years into the coronavirus pandemic, most people have a general idea of how the virus spreads and how to mitigate that spread. However, some questions remain about how fast the virus propagates and the most effective preventative measures. These questions are challenging because they require studying large volumes of aerosol particles for long times.
Schröder et al. studied the effects of coronavirus spread in confined spaces using an advanced particle tracking algorithm and a series of cameras and pulsed LEDs.
“We measured the flow optically around a full-scale breathing human model in a test room of 12 cubic meters,” said author Andreas Schröder. “We used up to 3 million tiny, helium-filled soap bubbles to investigate how aerosol particles, which are cyclically exhaled by a human being, would be transported and distributed inside such a room.”
The team used their setup to examine the effects of masks, face shields, and room dividers. They found that, beyond the filtering effect, all three measures dramatically reduce direct aerosol exposure by slowing the exhaled flow, which is then redirected upwards by the thermal plume of the human body. This slows the rate the aerosols mix with the rest of the room air.
The researchers are now looking to study aerosol propagation in more complex environments as part of a larger investigation into how virus particles are created and spread.
“For this, we work together with virologists, particle physicists, microbiologists and engineers,” said Schröder. “Our part will be the investigation of the flow and related aerosol particle transport mechanisms inside even larger populated rooms, like school classes, seminar rooms and restaurants.”
Source: “Large-scale volumetric flow studies on transport of aerosol particles using a breathing human model with and without face protections,” by A. Schröder, D. Schanz, J. Bosbach, M. Novara, R. Geisler, J. Agocs, and A. Kohl, Physics of Fluids (2022). The article can be accessed at https://doi.org/10.1063/5.0086383 .
This paper is part of the Flow and the Virus Collection, learn more here .
