3D Time-Dependent Model Of The Dusty-Gas Atmosphere Of Comet 67P/Churyumov-Gerasimenko: Recent Improvements. - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2010

3D Time-Dependent Model Of The Dusty-Gas Atmosphere Of Comet 67P/Churyumov-Gerasimenko: Recent Improvements.

Résumé

Under support from the French Space Agency (CNES), a 3D+t dusty-gas model of Comet 67P/Churyumov-Gerasimenko is being developed, to compute, from the first 2014 Rosetta orbital data, the aerodynamic forces exerted on the Rosetta orbiter and on the descent lander. We report the recently developed dust dynamics part of the code.

The multi-species (presently H2O and CO) gas code is optimized in terms of computational speed owing to the use of two complementary methods: (a) 3D+t Direct Simulation Monte Carlo (DSMC) runs in the non-equilibrium regions adjacent to the surface and very distant from it, and (b) solutions of the Navier-Stokes equations in-between. The model is used presently using Lamy et al. (Space Sci. Rev., 2007, 128, 23) coarse information on 67P nucleus shape and rotation, and a range of possible gas production rates Q for the early Rosetta observations at rh 3 AU (Q 1026 - 1027 s-1).

In the interim version, simplifying assumptions are made with respect to the physical processes of gas production and with respect to the dust grain structure (grain sphericity).

The dust code is based on the 3D+t Dust Monte-Carlo (DMC) approach of Crifo et al. ( Icarus, 2005, 176, 192) which allows for three forces: nucleus gravity, aerodynamic force, and solar radiation pressure.

The dynamics of grains of a large size range (submicron - millimeter) is described in detail, and three implications are discussed: (a) structure of the near-nucleus dust coma, (b) evolution of the nucleus surface, and (3) dust impacts on the lander.

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hal-04115370 , version 1 (02-06-2023)

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Vladimir Zakharov, A. V. Rodionov, Jean-François Crifo. 3D Time-Dependent Model Of The Dusty-Gas Atmosphere Of Comet 67P/Churyumov-Gerasimenko: Recent Improvements.. 42nd Annual Meeting of the DPS of the American Astronomical Society, Oct 2010, Pasadena, United States. pp.972. ⟨hal-04115370⟩
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