Deposition of particle pollution in turbulent forced-air cooling

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Deposition of particle pollution in turbulent forced-air cooling. / Stafford, Jason; Xu, Chen.

In: Aerosol Science and Technology, Vol. 55, No. 4, 08.02.2021, p. 486-500.

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@article{96c2ffab02214c5896dcc59062f1e5a4,
title = "Deposition of particle pollution in turbulent forced-air cooling",
abstract = "Rotating fans are the prevalent forced cooling method for heat generating equipment and buildings. As the concentration of atmospheric pollutants has increased, the accumulation of microscale and nanoscale particles on surfaces due to advection-diffusion has led to adverse mechanical, chemical and electrical effects that increase cooling demands and reduce the reliability of electronic equipment. Here, we uncover the mechanisms leading to enhanced deposition of particle matter (PM 2.5) on surfaces due to turbulent axial fan flows operating at Reynolds numbers, (Formula presented.) Qualitative observations of long-term particle deposition from the field were combined with in situ particle image velocimetry on a telecommunications base station, revealing the dominant role of impingement velocity and angle. Near-wall momentum transport for (Formula presented.) were explored using a quadrant analysis to uncover the contributions of turbulent events that promote particle deposition through turbulent diffusion and eddy impaction. By decomposing these events, the local transport behavior of fine particles from the bulk flow to the surface has been categorized. The transition from deposition to clean surfaces was accompanied by a decrease in shear velocity, turbulent stresses, and particle sweep motions with lower flux in the wall-normal direction. Finally, using these insights, selective filtering of coarse particles was found to promote the conditions that enhance the deposition of fine particle matter.",
keywords = "Environmental Chemistry, General Materials Science, Pollution",
author = "Jason Stafford and Chen Xu",
year = "2021",
month = feb,
day = "8",
doi = "10.1080/02786826.2021.1873237",
language = "English",
volume = "55",
pages = "486--500",
journal = "Aerosol Science and Technology",
issn = "0278-6826",
publisher = "Taylor & Francis",
number = "4",

}

RIS

TY - JOUR

T1 - Deposition of particle pollution in turbulent forced-air cooling

AU - Stafford, Jason

AU - Xu, Chen

PY - 2021/2/8

Y1 - 2021/2/8

N2 - Rotating fans are the prevalent forced cooling method for heat generating equipment and buildings. As the concentration of atmospheric pollutants has increased, the accumulation of microscale and nanoscale particles on surfaces due to advection-diffusion has led to adverse mechanical, chemical and electrical effects that increase cooling demands and reduce the reliability of electronic equipment. Here, we uncover the mechanisms leading to enhanced deposition of particle matter (PM 2.5) on surfaces due to turbulent axial fan flows operating at Reynolds numbers, (Formula presented.) Qualitative observations of long-term particle deposition from the field were combined with in situ particle image velocimetry on a telecommunications base station, revealing the dominant role of impingement velocity and angle. Near-wall momentum transport for (Formula presented.) were explored using a quadrant analysis to uncover the contributions of turbulent events that promote particle deposition through turbulent diffusion and eddy impaction. By decomposing these events, the local transport behavior of fine particles from the bulk flow to the surface has been categorized. The transition from deposition to clean surfaces was accompanied by a decrease in shear velocity, turbulent stresses, and particle sweep motions with lower flux in the wall-normal direction. Finally, using these insights, selective filtering of coarse particles was found to promote the conditions that enhance the deposition of fine particle matter.

AB - Rotating fans are the prevalent forced cooling method for heat generating equipment and buildings. As the concentration of atmospheric pollutants has increased, the accumulation of microscale and nanoscale particles on surfaces due to advection-diffusion has led to adverse mechanical, chemical and electrical effects that increase cooling demands and reduce the reliability of electronic equipment. Here, we uncover the mechanisms leading to enhanced deposition of particle matter (PM 2.5) on surfaces due to turbulent axial fan flows operating at Reynolds numbers, (Formula presented.) Qualitative observations of long-term particle deposition from the field were combined with in situ particle image velocimetry on a telecommunications base station, revealing the dominant role of impingement velocity and angle. Near-wall momentum transport for (Formula presented.) were explored using a quadrant analysis to uncover the contributions of turbulent events that promote particle deposition through turbulent diffusion and eddy impaction. By decomposing these events, the local transport behavior of fine particles from the bulk flow to the surface has been categorized. The transition from deposition to clean surfaces was accompanied by a decrease in shear velocity, turbulent stresses, and particle sweep motions with lower flux in the wall-normal direction. Finally, using these insights, selective filtering of coarse particles was found to promote the conditions that enhance the deposition of fine particle matter.

KW - Environmental Chemistry

KW - General Materials Science

KW - Pollution

UR - http://www.scopus.com/inward/record.url?scp=85100715570&partnerID=8YFLogxK

U2 - 10.1080/02786826.2021.1873237

DO - 10.1080/02786826.2021.1873237

M3 - Article

VL - 55

SP - 486

EP - 500

JO - Aerosol Science and Technology

JF - Aerosol Science and Technology

SN - 0278-6826

IS - 4

ER -