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NASA NTRS · 20170011059

Multi-Group Maximum Entropy Model for Translational Non-Equilibrium

Jayaraman, Vegnesh·Liu, Yen·Panesi, Marco
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Abstract

The aim of the current work is to describe a new model for flows in translational non- equilibrium. Starting from the statistical description of a gas proposed by Boltzmann, the model relies on a domain decomposition technique in velocity space. Using the maximum entropy principle, the logarithm of the distribution function in each velocity sub-domain (group) is expressed with a power series in molecular velocity. New governing equations are obtained using the method of weighted residuals by taking the velocity moments of the Boltzmann equation. The model is applied to a spatially homogeneous Boltzmann equation with a Bhatnagar-Gross-Krook1(BGK) model collision operator and the relaxation of an initial non-equilibrium distribution to a Maxwellian is studied using the model. In addition, numerical results obtained using the model for a 1D shock tube problem are also reported.

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Jayaraman, Vegnesh, Liu, Yen, Panesi, Marco. 2017-06-05. Multi-Group Maximum Entropy Model for Translational Non-Equilibrium. https://ntrs.nasa.gov/citations/20170011059

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