Coagulation of bipolarly charged ultrafine aerosol particles

Park, S.H.; Lee, K.W.; Okuyama, Kikuo

doi:10.1016/j.jaerosci.2004.10.013

Cited by 18 publications

(6 citation statements)

References 33 publications

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“…Ketzel et al (2016) simulated the time scale evolution of particle size distribution during vehicle exhaust emissions and dilution, specifically pointed out that in a closed environment, such as a road tunnel, the diffusion of particulate matter is generated by the limited airflow in the tunnel, which is different from the characteristics of an open environment. In a confined environment as a road tunnel the coagulation and deposition play an important role, as it also was concluded by Gidhagen et al (2003), Sturm et al (2003) and Park et al (2004).…”

Section: Introductionmentioning

confidence: 80%

Coagulation patterns and the impacts on traffic-related ultrafine particle dispersion in road tunnels employing dynamic mesh algorithms

Zhao

Yang

Song

et al. 2021

Environ Sci Pollut Res

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Following our simulation results in paper (Zhao et al., 2020). In this study we continue to analyze the diffusion mechanism of ultrafine particles and the particle coagulation phenomenon with the size range of 26~287 nm exhausted from the vehicles during the process of passing through a 100 m long tunnel using the Realizable k-ε model and the dynamic grid technique. In this paper, a three-dimensional model consisting of a 100 m highway tunnel and four sideby-side gasoline vehicles (L×W×H = 4.5 m×1.8 m×1.5 m) were established in the STAR-CCM+ computational fluid dynamics software. The gasoline vehicles travelled simultaneously under the different situations of three driving speeds of 60 km h -1 , 40 km h -1 and 20 km h -1 during the simulation. Through data analysis and research, it is found that the coagulation process of particles is very complicated, especially at low speeds. When the vehicle speed is 20 km h -1 , the variation of particle concentration at the vehicle wake near the tailpipe (at the vertical plane located 0.1 m behind the exhaust pipe) will cause a large error if the coagulation action is not taken into account. The relative error of the average particle concentration at 0.5 s of the vertical section 0.1m away from the exhaust pipe is as high as 193.51%. The relative error in the whole tunnel is only 2.82%, less than 5%, thus the influence of coagulation can be ignored for the whole tunnel. This study clarified the importance of coagulation in different areas and its influence on the diffusion of particulate matter, which is conducive to further analysis of the diffusion characteristics of particulate matter and can appreciably reduce the pollution degree in the tunnel by changing the coagulation efficiency of particulate matter in the future.

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Section: Introductionmentioning

confidence: 80%

Coagulation patterns and the impacts on traffic-related ultrafine particle dispersion in road tunnels employing dynamic mesh algorithms

Zhao

Yang

Song

et al. 2021

Environ Sci Pollut Res

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“…The coagulation rate of a bidispersed aerosol consisting of oppositely charged particles of rather different size was calculated numerically based on well-known population balance models, which have been used many times before to simulate changes in aerosol charge or size distribution (e.g., Eliasson et al 1991;Park et al 2005;Verdoold and Marijnissen. 2011).…”

Section: Model Expressions Usedmentioning

confidence: 99%

An Aerosol-Based Process for Electrostatic Coating of Particle Surfaces with Nanoparticles

Sigmund¹,

Yu²,

Meyer³

et al. 2013

Aerosol Science and Technology

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An aerosol-based process for coating the surface of arbitrary "carrier" particles with other types of (smaller) "coating" particles via mutual electrostatic attraction is described. Its practical viability was tested by depositing negatively charged 12-nm palladium particles on 250-nm silica spheres carrying a charge of approximately +40 units each. At respective concentrations of 3 to 8 × 10 6 particles per cm 3 (with a charge fraction of about 25%) and 1 × 10 4 particles per cm 3 , the deposition process runs to completion (i.e., to neutralization of the carrier particles) within less than a minute. Comparative estimates show that electrostatically enhanced deposition rates are up to 50 times higher than purely thermal collisions. Transmission electron micrographs show a fairly uniform distribution of coating particles across the surface of the carrier particles. The electrostatic coating kinetics were determined experimentally via the charge loss of the carrier particles and compared also to numerical simulations using Zebel's model for electrostatic enhancement of the collision kernel. Measured rates were generally within 10-15% of the simulations, except for the very early stages of attachment (the first 10 s), where agreement was found to be rather sensitive to the coating particle concentration, possibly due to space charge effects.

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“…But Park et al (2005), in their modeling studies, bi-polar diffusion charging can significantly increase the coagulation rate of aerosols. Bi-polar diffusion charging of non-radioactive aerosols by using Am-241 Alpha sources was compared with that of soft X-ray source of 9.5 keV by Lee et al (2005).…”

Section: Introductionmentioning

confidence: 99%

An experimental study on the charging of non-radioactive aerosols with and without the presence of gamma radiation

Subramanian

Kumar

Baskaran

et al. 2012

Journal of Aerosol Science

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Coagulation of bipolarly charged ultrafine aerosol particles

Cited by 18 publications

References 33 publications

Coagulation patterns and the impacts on traffic-related ultrafine particle dispersion in road tunnels employing dynamic mesh algorithms

Coagulation patterns and the impacts on traffic-related ultrafine particle dispersion in road tunnels employing dynamic mesh algorithms

An Aerosol-Based Process for Electrostatic Coating of Particle Surfaces with Nanoparticles

An experimental study on the charging of non-radioactive aerosols with and without the presence of gamma radiation

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