Direct Numerical Simulation of Rarefied Planetary Atmospheres
Direct Numerical Simulation of Rarefied Planetary Atmospheres
by J. Victor Austin
Contents:
Also, please see our work on the
Lunar Prospector Impact Page.
Welcome to this work-in-progress which describes the efforts at the
Computational Fluid Physics Lab to model
low-density planetary atmospheric flows using the
Direct Simulation Monte Carlo rarefied gas dynamics computational model.
Work on this project is being continued by
Mr. Ju Zhang. Here are some of the earlier results:
Simulation of an Ionian Volcano Using DSMC.
Results of a simulation of a condensing volcano on Io using the Direct
Simulation Monte Carlo (DSMC) method. Mach number contours are shown
in color with velocity streamlines overlaid. The volcano is
axi-symmetric about the left edge of the figure. Sulfur-dioxide gas is
exhausted vertically at Mach three from a volcanic vent eight
kilometers in radius (lower left of figure). As the plume rises it
expands and cools which increases the Mach number. A canopy-shaped
shock then turns the flow outward (seen at altitude of approximately
75km). The outward moving gas continues to cool due to expansion and
also accelerates toward the surface, causing the flow to again become
supersonic. Another shock (often referred to as the re-entry shock)
then slows the falling gas and turns it outward again. The gas then
condenses onto the cold surface of Io (lower edge of figure).
Animations of a volcanic plume.
J. V. Austin and D. B. Goldstein, Simulation of
Supersonic Rarefied Atmospheric Flows on Io, to appear in
21st International Symposium on Rarefied Gas Dynamics, 1998.
J. V. Austin and D. B. Goldstein, Rarefied Gas Model of Io's
Sublimation-Driven Atmosphere, submitted to
Icarus, September, 1998.
J. V. Austin and D. B. Goldstein, Direct Numerical Simulation of
Circumplanetary Winds on Io, Bulletin of the
American Astronomical Society, Vol. 29, No. 3, 1997, pp. 1004.
J. V. Austin and D. B. Goldstein, Direct Numerical Simulation of
Low-Density Atmospheric Flow on Io, M. Capitelli (ed.),
Molecular Physics and Hypersonic Flows, Kluwer
Academic Publishers, 1996, pp. 749-758.
J. V. Austin and D. B. Goldstein, Direct Numerical Simulation of
Pluto's Extended Atmosphere, P. Boyce (ed.), Bulletin of the
American Astronomical Society, Vol. 28, No. 3, 1996, pp. 1079.
J. V. Austin and D. B. Goldstein, Direct Numerical Simulation of a
Volcanic Plume on Io, N. Baggett (ed.), Bulletin of the
American Physical Society, Series II, Vol. 39, No. 9, November
1994, pp. 1884.
Last revised: April 2, 2003
Simulation of an Ionian Volcano Using DSMC.
Results of a simulation of a condensing volcano on Io using the Direct
Simulation Monte Carlo (DSMC) method. Mach number contours are shown
in color with velocity streamlines overlaid. The volcano is
axi-symmetric about the left edge of the figure. Sulfur-dioxide gas is
exhausted vertically at Mach three from a volcanic vent eight
kilometers in radius (lower left of figure). As the plume rises it
expands and cools which increases the Mach number. A canopy-shaped
shock then turns the flow outward (seen at altitude of approximately
75km). The outward moving gas continues to cool due to expansion and
also accelerates toward the surface, causing the flow to again become
supersonic. Another shock (often referred to as the re-entry shock)
then slows the falling gas and turns it outward again. The gas then
condenses onto the cold surface of Io (lower edge of figure).