Showing papers by "James D. Iversen published in 2006"
TL;DR: In this paper, the Arizona State University Vortex Generator (ASUVG) was used to simulate dust flux in dust devils and the results were compared with data from natural dust devils on Earth and Mars.
Abstract: 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−3 in 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 (ΔP) and is less determined by size of the vortex. This is critical in scaling the laboratory results to natural dust devils.
39 citations
01 Mar 2006
TL;DR: Neakrase et al. as mentioned in this paper extended particle threshold laboratory simulations for the simulation of Earth and Mars dust devils and reported that the results showed that the extension of threshold laboratory simulation can significantly improve the performance of particle threshold simulations.
Abstract: Dust devils on Earth and Mars: Extension of particle threshold laboratory simulations Conference Item How to cite: Neakrase, Lynn D. V.; Greeley, Ronald; Haan, Frederick L.; Sarkar, Partha; Iversen, James D.; Balme, Matthew R. and Eddlemon, Eric E. (2006). Dust devils on Earth and Mars: Extension of particle threshold laboratory simulations. In: 37th Lunar and Planetary Science Conference, 13-17 March 2006, Houston, Texas, USA.
2 citations