Effect of turbulent thermal plume on aspiration efficiency of micro-particles

Naseri, Arash; Abouali, Omid; Ahmadi, Goodarz

doi:10.1016/j.buildenv.2017.03.018

Cited by 28 publications

(9 citation statements)

References 50 publications

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“…All VSs show in common the presence of convective flows around and above the person toward the ceiling, which are induced by thermal plumes around the person. The mean airflow velocities in this region are between 0.05 and 0.25 m/s and are in good agreement with measurement data. , …”

Section: Resultssupporting

confidence: 86%

Estimation of Inhalation Exposure on the Basis of Airborne Nanomaterial Release Data and Propagation Modeling

Göhler

Gritzki

Rösler

et al. 2018

ACS Sustainable Chem. Eng.

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The lack of data for inhalation exposure concerning the handling of nanostructured materials is limiting the current nanomaterial risk assessment. However, there are numerous studies dealing with the origin of exposure, i.e., the release. The link between release and exposure are transport and transformation phenomena. Thus, propagation modeling was used to simulate transport from source to breathing zone in order to estimate quantitative exposure levels from measured release data for selected scenarios. On the basis of three ventilation and five release scenarios, exposure levels were calculated with and without human thermal plumes for both the nearfield and the farfield. Results show that the often neglected human-induced convective airflow can have a strong impact on the level of exposure, especially for natural ventilation or non-well-designed technical ventilation systems as typical for nonindustrial consumers or handicraft businesses.

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Section: Resultssupporting

confidence: 86%

Estimation of Inhalation Exposure on the Basis of Airborne Nanomaterial Release Data and Propagation Modeling

Göhler

Gritzki

Rösler

et al. 2018

ACS Sustainable Chem. Eng.

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“…The main influence of temperature was reflected in the human body's thermal plume and the buoyancy of particles ( Zhu et al, 2020 ; Naseri et al, 2017 ; Licina et al, 2014 ). They were also taken into account.…”

Section: Methodsmentioning

confidence: 99%

COVID-19 virus released from larynx might cause a higher exposure dose in indoor environment

Weng

2021

Environmental Research

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COVID-19 virus can replicate in the infected individual's larynx independently, which is different from other viruses that replicate in lungs only, e.g. SARS. It might contribute to the fast spread of COVID-19. However, there are few scientific reports about quantitative comparison of COVID-19 exposure dose (inhalation dose and adhesion dose) for the susceptible individual when the viruses were released from the larynx or lungs. In this paper, a typical numerical model was built based on a breathing human model with real respiratory tract. By using a computational fluid dynamics (CFD) method, two kinds of virus released sites in the infected individual's respiratory tract (larynx, lungs), seven kinds of particle sizes between 1 and 50 μm, three kinds of expiratory flow rates: calm (10 L/min), moderate (30 L/min) and intense (90 L/min) were used to compare the particle deposition proportion and escape proportion. The inhalation dose and the adhesion dose of the susceptible individual were quantified. The results showed that COVID-19 virus-containing droplets and aerosols might be released into the environment at higher proportions (39.1%–44.2%) than viruses that replicate in lungs only (15.3%–37.1%). The exposure doses (inhalation dose and adhesion dose) of the susceptible individual in different situations were discussed. The susceptible individual suffered a higher exposure dose when the viruses were released from the larynx rather than lungs (the difference for 1 μm particles was 1.2–2.2 times). This study provides a possible explanation for the higher transmission risk of COVID-19 virus compared to other viruses and some control advice of COVID-19 in typical indoor environments were also discussed.

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“…(2012) . Naseri et al. (2017a) performed a series of computational modeling and analyzed the influence of the thermal plume on particle aspiration efficiency when the body temperature is higher or lower than the ambient.…”

Section: Inhalation Stagementioning

confidence: 99%

Host-to-host airborne transmission as a multiphase flow problem for science-based social distance guidelines

Balachandar

Zaleski

Soldati

et al. 2020

International Journal of Multiphase Flow

169

194

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COVID-19 pandemic has strikingly demonstrated how important it is to develop fundamental knowledge related to generation, transport and inhalation of pathogen-laden droplets and their subsequent possible fate as airborne particles, or aerosols, in the context of human to human transmission. It is also increasingly clear that airborne transmission is an important contributor to rapid spreading of the disease. In this paper, we discuss the processes of droplet generation by exhalation, their potential transformation into airborne particles by evaporation, transport over long distances by the exhaled puff and by ambient air turbulence, and final inhalation by the receiving host as interconnected multiphase flow processes. A simple model for the time evolution of droplet/aerosol concentration is presented based on a theoretical analysis of the relevant physical processes. The modeling framework along with detailed experiments and simulations can be used to study a wide variety of scenarios involving breathing, talking, coughing and sneezing and in a number of environmental conditions, as humid or dry atmosphere, confined or open environment. Although a number of questions remain open on the physics of evaporation and coupling with persistence of the virus, it is clear that with a more reliable understanding of the underlying flow physics of virus transmission one can set the foundation for an improved methodology in designing case-specific social distancing and infection control guidelines.

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Effect of turbulent thermal plume on aspiration efficiency of micro-particles

Cited by 28 publications

References 50 publications

Estimation of Inhalation Exposure on the Basis of Airborne Nanomaterial Release Data and Propagation Modeling

Estimation of Inhalation Exposure on the Basis of Airborne Nanomaterial Release Data and Propagation Modeling

COVID-19 virus released from larynx might cause a higher exposure dose in indoor environment

Host-to-host airborne transmission as a multiphase flow problem for science-based social distance guidelines

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