CFD Analysis of Coronavirus Particle Transmission with Protective Shields

This study presents a computational fluid dynamics simulation examining the effectiveness of face shields in preventing coronavirus particle transmission during conversation between individuals at close proximity.

Model Development

A three-dimensional computational domain (1.6m × 2m × 2.6m) was created using Design Modeler software, representing two individuals facing each other at a distance of 80cm—below recommended social distancing guidelines. One individual was designated as infected, with their mouth serving as the source of viral particles during speech.

The computational mesh was generated using ANSYS Meshing software with 724,076 elements. Given the time-dependent nature of particle dispersion, a transient solver approach was implemented with time steps of 0.001 seconds.

Simulation Methodology

The Discrete Phase Model (DPM) was employed to track individual virus particles within the continuous airflow medium. Key simulation parameters included:

• Particle classification: Inert type
• Injection method: Surface-based emission from patient’s mouth
• Particle diameter: 1 micrometer (10⁻⁶ m)
• Particle temperature: 310K (body temperature)
• Emission duration: 0-20 seconds
• Velocity profile: Sinusoidal function with 0.33 m/s maximum velocity
• Flow rate: Proportionally linked to particle velocity

Boundary conditions were configured with:

• “Escape” condition at patient’s mouth (allowing particle emission)
• “Trap” condition at mask/shield surfaces (capturing particles)

The RNG k-epsilon turbulence model was utilized alongside the energy equation to accurately capture flow dynamics and temperature distribution within the domain.

Results and Analysis

Particle tracking visualizations were generated at various time intervals throughout the 20-second simulation period, with particles colored according to residence time and velocity. The results clearly demonstrated that protective face shields effectively intercepted viral particles expelled during speech, preventing their transmission to the healthy individual.

The periodic emission pattern of particles from the infected individual’s mouth was successfully captured, showing how particles accumulated on the shield’s inner surface rather than reaching the second person. This confirms the effectiveness of face shields as a protective barrier in close-proximity interactions, supporting medical recommendations for their use when maintaining proper social distance is challenging.