Dynamic simulation of contaminant inleakage produced by human walking into control room

Chang, Le; Tu, Shuyang; Ye, Wei; Xu, Zhang

doi:10.1016/j.ijheatmasstransfer.2017.06.040

Cited by 35 publications

(13 citation statements)

References 28 publications

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“…For convergence criteria, the simulation was assumed to converge if the residuals for continuity, energy, and mass were less than 1e‐06, 1e‐06, and 1e‐03, respectively. This convergence criterion was verified and recommended by numerous studies (Chang et al., ; Chow & Wang, ; Poussou et al., ; Saarinen et al., ).…”

Section: Case Studymentioning

confidence: 53%

“…For mesh adapting, the mesh was generated by the ANSYS meshing algorithm. For mesh type, because of the complexity of the model, tetrahedron cells were filled in all the air domains in the room space and ventilation system (Chang et al., ; Chang, Zhang, Wang, & Gao, ).…”

Section: Case Studymentioning

confidence: 99%

“…To choose an appropriate mesh size, we ran the same simulation on progressively finer meshes (1.0e + 06, 2.2e + 06, and 4.8e + 06 cells) by changing global mesh sizing parameters and local refinement, especially the mesh size around the air outlets and breathing zones of occupants. After comparing the Cl 2 mass fraction results of a three‐mesh scale (independence test) (Chang et al., , ) at the door surface (D3) during the first 60 seconds in Case C4‐S10, Fig. (a) shows that the mesh with 2.2e + 06 cells was fine enough, with the maximum deviation of 1.9% from the solution of 4.8e+06 cells.…”

Section: Case Studymentioning

confidence: 99%

“…The time step for the calculation was set to 0.25 seconds, which has been adopted for the simulation of contaminant transport in several studies (Cai et al., ; Cai, Long, Li, Kong et al., ; Chen et al., ). To validate this value, we also compared the Cl 2 mass fraction results of three time steps—0.1 seconds, 0.25 seconds, and 0.5 seconds (independence test) (Chang et al., , )—at the door surface (D3) during the first 60 seconds in Case C4‐S10. Fig.…”

Section: Case Studymentioning

confidence: 99%

“…These models can be sorted into four categories according to different methods in the mathematical process (Fontanini, Vaidya, & Ganapathysubramanian, ; Fontanini, Vaidya, Passalacqua, & Ganapathysubramanian, ; Gao, Zeng, Wu, Ding, & Zhang, ; Hussein, Wierzbicka, Löndahl, Lazaridis, & Hänninen, ; Shao, Li, Liang, & Shan, ): (1) Lagrangian flux models, (2) Gaussian models, (3) computational fluid dynamics (CFD) methods, and (4) analytical methods. Many investigations using CFD simulation have indicated that CFD is accurate in predicting the air distribution and the pollutant concentration field inside buildings (Chang, Tu, Ye, & Zhang, ; Chow & Wang, ). For the cases with complex geometries, CFD is more effective for model building and calculation (Poussou, Mazumdar, Plesniak, Sojka, & Chen, ; Saarinen, Kalliomaki, Tang, & Koskela, ).…”

Section: Introductionmentioning

confidence: 99%

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A Risk Assessment Approach for Evaluating the Impact of Toxic Contaminants Released Indoors by Considering Various Emergency Ventilation and Evacuation Strategies

et al. 2018

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The release of toxic airborne contaminants resulting from terrorist attacks on buildings can lead to disastrous consequences. To evaluate and reduce the effects of these emergencies, various methods and models have been developed in the past few years. Such work has provided effective tools for the building management system to do risk assessment of the contaminated areas. Although risk analysis methods to describe the contaminant dispersion scenarios made significant progress, these approaches did not generally consider the releasing scenario occurring in the ventilation system and the effect of human behavior during the developing process of an emergency event. Emergency strategies chosen by the decisionmaker are not always associated with the early-warning system, such as the sensor monitoring network and the source identification system inside the building. This study aims to provide a risk assessment model considering both the variation of contaminant concentration and occupant distribution after the release of toxic agents to obtain the exposure risk for people indoors. The contaminant dispersion is simulated using computational fluid dynamics. The evacuation process for people is modeled using Pathfinder, and the exposure risk for occupants under various emergency strategies is calculated using the efficiency factor of the contaminant source. The results of the exposure risk for 40 basic cases are discussed, and the optimal ventilation mode for these specific cases is recommended. Next, the impact of the variation of human behavior, contaminant detection time needed by sensors, and source identification time needed by inverse modeling on the exposure risk for people indoor is studied. The uncertainty and reproducibility of the numerical simulations are emphatically discussed in the Supporting Information.

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Section: Case Studymentioning

confidence: 53%

Section: Case Studymentioning

confidence: 99%

Section: Case Studymentioning

confidence: 99%

Section: Case Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A Risk Assessment Approach for Evaluating the Impact of Toxic Contaminants Released Indoors by Considering Various Emergency Ventilation and Evacuation Strategies

et al. 2018

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Study on contaminant distribution in a mobile BSL-4 laboratory based on multi-region directional airflow

Wang

Miao

Chen

et al. 2021

Environ Sci Pollut Res

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The outbreak of COVID-19 has caused increasing public attention to laboratory-acquired infections (LAIs), especially for a mobile Bio-Safety Level 4 Lab (BSL-4) with high potential of exposure. In this paper, the distribution and removal mechanism of bioaerosols in the biosafety laboratory were studied. A simulation model of airflow distribution in the opening and closing state of air-tight door was established and verified. The results showed that the airflow entrainment velocity during the opening of the door was approximately 0.12 m/s. It increased the probability of vortex generation in the laboratory. The deposition rate of particles was doubled when the air-tight door opening is compared with air-tight door closing. Besides, nearly 80% of the particles deposited on the surface of the wall and ceiling, increasing the possibility of LAIs. The findings of this paper could provide new scientific methods for high-level biosafety laboratories to avoid cross-infection. Moreover, future work regarding air-tight door rotation speed regulation and control should be emphasized.Keywords Laboratory-acquired infections . Mobile Bio-Safety Level 4 Lab . Removal mechanism . Airflow distribution . Bioaerosols . Entrainment velocity Highlights• This study was conducted based on a mobile BSL-4 laboratory.• The mechanism of bioaerosol diffusion between multi-region was analyzed.• Entrainment velocity altered the locations of high concentration zones of bioaerosols.• Opening or closing of airtight doors raises the possibility of cross-infection.• The mode of interaction between airflow and bioaerosols was explored.

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Influence of exterior door opening on the heating consumption of a passive residential house

2020

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Dynamic simulation of contaminant inleakage produced by human walking into control room

Cited by 35 publications

References 28 publications

A Risk Assessment Approach for Evaluating the Impact of Toxic Contaminants Released Indoors by Considering Various Emergency Ventilation and Evacuation Strategies

A Risk Assessment Approach for Evaluating the Impact of Toxic Contaminants Released Indoors by Considering Various Emergency Ventilation and Evacuation Strategies

Study on contaminant distribution in a mobile BSL-4 laboratory based on multi-region directional airflow

Influence of exterior door opening on the heating consumption of a passive residential house

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