Visualization and Quantification of Facemask Leakage Flows and Interpersonal Transmission with Varying Face Coverings DOI Open Access
Xiuhua Si,

Jensen S. Xi,

H. Talaat

et al.

Published: June 7, 2024

Although mask-wearing is now widespread, knowledge of how to quantify or improve its performance remains surprisingly limited and largely based on empirical evidence. The objective this study was visualize the expiratory airflows from facemasks evaluate aerosol transmission between two persons. Different visualization methods were explored, including Schlieren optical system, laser/LED-particle imaging thermal camera, vapor-SarGel system. leakage flows escaped aerosols quantified using a hotwire anemometer particle counter, respectively. results show that reduces exhaled flow velocity 2~4 m/s (with no facemask) around 0.1 m/s, thus decreasing droplet speeds. Cloth, surgical, KN95 masks showed varying at nose top, sides, chin. rate also differed inhalation exhalation. neck gaiter has low filtration efficiency high fractions, providing protection efficiency. There considerable deposition in mouth-nose area, as well neck, chin, jaw, which heightened risk self-inoculation through spontaneous face-touching. A face shield plus surgical mask greatly reduced droplets head, face, indicating double coverings can be highly effective when single insufficient. system provided practical approach interpersonal under close contact scenarios with different coverings.

Language: Английский

Recent Developments and Future Directions in Flow Visualization: Experiments and Techniques DOI Creative Commons
Mingming Ge, Guangjian Zhang, Xinlei Zhang

et al.

Fluids, Journal Year: 2025, Volume and Issue: 10(2), P. 23 - 23

Published: Jan. 22, 2025

Flow visualization has long been a critical tool for understanding complex fluid dynamics in both natural and engineered systems [...]

Language: Английский

Citations

0
Top and Side Leakage Effects on Thermoregulation and Moisture Retention with Facemask Wearing DOI Creative Commons
Kian Barari,

Xiuhua Si,

Rozhin Hajian

et al.

Journal of Respiration, Journal Year: 2025, Volume and Issue: 5(2), P. 5 - 5

Published: April 3, 2025

Background/Objectives: Mask-wearing-induced discomfort often leads to unconscious loosening of the mask relieve discomfort, thereby compromising protective efficacy. This study investigated how leakage flows affect mask-associated thermoregulation and vapor trapping inform better designs. An integrated ambience–mask–face–airway model with various mask-wearing misfits was developed. Methods: The transient warming/cooling effects, thermal buoyancy force, tissue heat generation, phase change, fluid/heat/mass transfer through a porous medium were considered in this model, which validated using Schlieren imaging, camera, velocity/temperature measurements. Leakages from top side analyzed comparison no-leak scenario under cyclic respiration conditions. Results: A significant inverse relationship observed between facial temperature/humidity. equivalent impact forces exhalation flow inertia both experimentally numerically, indicating delicate balance natural convection forced convection, is sensitive critical thermo-humidity regulation. For given gap, fraction not constant within one breathing cycle but constantly increased during exhalation. Persistently higher temperatures found nose region throughout sealed mitigated inhalation when gaps present. Vapor condensation occurred all cases. Conclusions: temporal variation profiles location highlighting feasibility leveraging temperature relative humidity test fit quantify fraction.

Language: Английский

Citations

0
Visualization and Quantification of Facemask Leakage Flows and Interpersonal Transmission with Varying Face Coverings DOI Open Access
Xiuhua Si,

Jensen S. Xi,

H. Talaat

et al.

Published: June 7, 2024

Although mask-wearing is now widespread, knowledge of how to quantify or improve its performance remains surprisingly limited and largely based on empirical evidence. The objective this study was visualize the expiratory airflows from facemasks evaluate aerosol transmission between two persons. Different visualization methods were explored, including Schlieren optical system, laser/LED-particle imaging thermal camera, vapor-SarGel system. leakage flows escaped aerosols quantified using a hotwire anemometer particle counter, respectively. results show that reduces exhaled flow velocity 2~4 m/s (with no facemask) around 0.1 m/s, thus decreasing droplet speeds. Cloth, surgical, KN95 masks showed varying at nose top, sides, chin. rate also differed inhalation exhalation. neck gaiter has low filtration efficiency high fractions, providing protection efficiency. There considerable deposition in mouth-nose area, as well neck, chin, jaw, which heightened risk self-inoculation through spontaneous face-touching. A face shield plus surgical mask greatly reduced droplets head, face, indicating double coverings can be highly effective when single insufficient. system provided practical approach interpersonal under close contact scenarios with different coverings.

Language: Английский

Citations

3