### Abstract

Dispersion of small particles emitted from an area source at the surface into a fully developed high-Reynolds-number boundary layer flow is studied as a theoretical model for pollen dispersion in the neutral atmospheric boundary layer. The particle plume above the area source is assumed to behave as a particle concentration boundary layer. Boundary layer scaling and the assumption of self-preservation lead to an analytical solution in the form of a similarity function that has an additional dependence on the ratio of gravitational settling and turbulent diffusion velocities. Similar arguments are used to predict patterns of deposition onto the surface downstream of the source. Theoretical predictions are tested using a suite of large-eddy-simulation numerical experiments, with good agreement. The combined analysis of theoretical and numerical results reveals interesting features in the patterns of downstream deposition, such as non-monotonic trends in isolation distance with particle settling velocity and surprisingly large isolation distances for practically relevant parameter ranges. Possible effects of turbulence on effective settling velocity are highlighted.

Original language | English (US) |
---|---|

Pages (from-to) | 1-26 |

Number of pages | 26 |

Journal | Journal of Fluid Mechanics |

Volume | 683 |

DOIs | |

State | Published - Sep 25 2011 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering

### Cite this

*Journal of Fluid Mechanics*,

*683*, 1-26. https://doi.org/10.1017/jfm.2011.243

}

*Journal of Fluid Mechanics*, vol. 683, pp. 1-26. https://doi.org/10.1017/jfm.2011.243

**Particle boundary layer above and downstream of an area source : Scaling, simulations, and pollen transport.** / Chamecki, Marcelo; Meneveau, Charles.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Particle boundary layer above and downstream of an area source

T2 - Scaling, simulations, and pollen transport

AU - Chamecki, Marcelo

AU - Meneveau, Charles

PY - 2011/9/25

Y1 - 2011/9/25

N2 - Dispersion of small particles emitted from an area source at the surface into a fully developed high-Reynolds-number boundary layer flow is studied as a theoretical model for pollen dispersion in the neutral atmospheric boundary layer. The particle plume above the area source is assumed to behave as a particle concentration boundary layer. Boundary layer scaling and the assumption of self-preservation lead to an analytical solution in the form of a similarity function that has an additional dependence on the ratio of gravitational settling and turbulent diffusion velocities. Similar arguments are used to predict patterns of deposition onto the surface downstream of the source. Theoretical predictions are tested using a suite of large-eddy-simulation numerical experiments, with good agreement. The combined analysis of theoretical and numerical results reveals interesting features in the patterns of downstream deposition, such as non-monotonic trends in isolation distance with particle settling velocity and surprisingly large isolation distances for practically relevant parameter ranges. Possible effects of turbulence on effective settling velocity are highlighted.

AB - Dispersion of small particles emitted from an area source at the surface into a fully developed high-Reynolds-number boundary layer flow is studied as a theoretical model for pollen dispersion in the neutral atmospheric boundary layer. The particle plume above the area source is assumed to behave as a particle concentration boundary layer. Boundary layer scaling and the assumption of self-preservation lead to an analytical solution in the form of a similarity function that has an additional dependence on the ratio of gravitational settling and turbulent diffusion velocities. Similar arguments are used to predict patterns of deposition onto the surface downstream of the source. Theoretical predictions are tested using a suite of large-eddy-simulation numerical experiments, with good agreement. The combined analysis of theoretical and numerical results reveals interesting features in the patterns of downstream deposition, such as non-monotonic trends in isolation distance with particle settling velocity and surprisingly large isolation distances for practically relevant parameter ranges. Possible effects of turbulence on effective settling velocity are highlighted.

UR - http://www.scopus.com/inward/record.url?scp=80053169353&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80053169353&partnerID=8YFLogxK

U2 - 10.1017/jfm.2011.243

DO - 10.1017/jfm.2011.243

M3 - Article

AN - SCOPUS:80053169353

VL - 683

SP - 1

EP - 26

JO - Journal of Fluid Mechanics

JF - Journal of Fluid Mechanics

SN - 0022-1120

ER -