Journal Article

PreJuSER-10006

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Comparison of experimental and numerical studies of the performance characteristics of a pumped counterflow virtual impactor

Kulkarni, G. ; Pekour, M. ; Afchine, A.FZJ* ; Murphy, D. M. ; Cziczo, J.

2011
Taylor & Francis Philadelphia, Pa

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Please use a persistent id in citations: doi:10.1080/02786826.2010.539291

Abstract: Experiments and Computational Fluid Dynamic (CFD) simulations were performed to evaluate the performance characteristics of a Pumped Counterflow Virtual Impactor (PCVI). The diameter at which 50% of the particles were transmitted was determined for various flow configurations. Experimentally determined 50% cut sizes varied from 2.2 to 4.8 micrometers and CFD predicted diameters agreed within +/- 0.4 micrometers. Both experimental and CFD results showed similar transmission efficiency (TE) curves. CFD TE was always greater than experimental results, most likely due to impaction losses in fittings not included in the simulations. Ideal transmission, corresponding to 100% TE, was never realized in either case due to impaction losses and small-scale flow features such as eddies. Areas where CFD simulations showed such flow recirculation zones were also found to be the locations where particulate residue was deposited during experiments. CFD parametric tests showed that PCVI performance can be affected by the nozzle geometry and misalignment between the nozzle and collector orifice. We conclude that CFD can be used with confidence for counter-flow virtual impactor (CVI) design. Modifications to improve the performance characteristics of the PCVI are suggested.

Keyword(s): J

Note: Funding of this work was provided by the Pacific Northwest National Laboratory Aerosol and Climate Initiative and NOAA base funding. We wish to thank Karl Froyd for useful discussions.

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Research Program(s):

1. Atmosphäre und Klima (P23)

Appears in the scientific report 2011

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