Détail de la notice
Titre du Document
Dust flux within dust devils : Preliminary laboratory simulations
Auteur(s)
NEAKRASE Lynn D. V. ; GREELEY Ronald ; IVERSEN James D. ; ...
Résumé
[1] Laboratory simulations using the Arizona State University Vortex Generator (ASUVG) were run to simulate dust flux in dust devils. These tests used particles 2 μm in diameter and 2600 kg m-3in density, and the results were compared with data from natural dust devils on Earth and Mars. Typically, the cores of dust devils (regardless of planetary environment) have a pressure drop of ∼0.2-1.5 percent of ambient atmospheric pressure. Core pressure drops in our experiments ranged from ∼0.01 to 5.00 percent of ambient pressure (10 mbar Mars cases and 1000 mbar for Earth cases). Flux experiments were run at vortex tangential wind velocities of 1 to 42 m s-1; typically ∼35-50 percent above threshold values for the particles used. Dust flux was determined by time averaged measurements of mass loss for a given vortex size. Dust fluxes of ∼10-3 kg m-2 s-1 were obtained, similar to estimates for flux for dust devils on Earth and Mars, regardless of core size. Vortex strength appears to be closely related to the strength of the pressure drop in the core (AP) and is less determined by size of the vortex. This is critical in scaling the laboratory results to natural dust devils.
Editeur
American Geophysical Union
Type du document
Conférence : Dust Devils on Earth and Mars. Workshop, 2005-08
Identifiant
ISSN : 0094-8276 CODEN : GPRLAJ
Source
Geophysical research letters A. 2006, vol. 33, n° 19, [L19S09.1-L19S09.5] [bibl. : 20 ref.]
Langue
Anglais
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