Technical note: Dispersion of cooking-generated aerosols from an urban street canyon
-
Published:2022-03-01
Issue:4
Volume:22
Page:2703-2726
-
ISSN:1680-7324
-
Container-title:Atmospheric Chemistry and Physics
-
language:en
-
Short-container-title:Atmos. Chem. Phys.
Author:
Gao Shang, Kurppa MonaORCID, Chan Chak K.ORCID, Ngan Keith
Abstract
Abstract. The dispersion of cooking-generated aerosols from an urban street canyon is examined with building-resolving computational fluid dynamics (CFD). Using a comprehensive urban CFD model (PALM) with a sectional aerosol module (SALSA), emissions from deep-frying and boiling are considered for near-ground and elevated sources. With representative choices of the source flux, the inclusion of aerosol dynamic processes decreases the mean canyon-averaged number concentration by 15 %–40 % for cooking emissions, whereas the effect is significantly weaker for traffic-generated aerosols. The effects of deposition and coagulation are comparable for boiling, but coagulation dominates for deep-frying. Deposition is maximised inside the leeward corner vortices, while coagulation increases away from the source. The characteristic timescales are invoked to explain the spatial structure of deposition and coagulation. In particular, the relative difference between number concentrations for simulations with and without coagulation is strongly correlated with the ageing of particles along fluid trajectories or the mean tracer age. It is argued that, for a specific emission spectrum, the qualitative nature of the aerosol dynamics within urban canopies is determined by the ratio of the aerosol timescales to the relevant dynamical timescale (e.g. the mean age of air).
Funder
City University of Hong Kong Environment and Conservation Fund
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference51 articles.
1. Ackerman, A. S., Toon, O. B., and Hobbs, P. V.: Numerical modeling of ship
tracks produced by injections of cloud condensation nuclei into marine
stratiform clouds, J. Geophys. Res.-Atmos., 100, 7121–7133, 1995. a 2. Baik, J.-J., Kang, Y.-S., and Kim, J.-J.: Modeling reactive pollutant
dispersion in an urban street canyon, Atmos. Environ., 41, 934–949, 2007. a 3. Brown, M. J., Lawson, R. E., DeCroix, D. S., and Lee, R.: Comparison of
centerline velocity measurements obtained around 2D and 3D building arrays in
a wind tunnel, Int. Soc. Environ. Hydraulics, Tempe, AZ, 5, https://digital.library.unt.edu/ark:/67531/metadc716934/ (last access: 20 February 2022), 2001. a, b 4. Chang, J. C. and Hanna, S. R.: Air quality model performance evaluation,
Meteorol. Atmos. Phys., 87, 167–196, 2004. a 5. Cui, Z., Cai, X., and J. Baker, C.: Large-eddy simulation of turbulent flow in
a street canyon, Q. J. Roy. Meteor. Soc., 130, 1373–1394, 2004. a
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|