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A unified stochastic particle method based on the Bhatnagar-Gross-Krook model for polyatomic gases and its combination with DSMC.
- Source :
-
Journal of Computational Physics . Dec2022, Vol. 471, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
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Abstract
- • A particle-particle hybrid approach by combining the USP-BGK and DSMC methods is developed for polyatomic gases. • The USP-BGK method employs an ES-BGK model with discrete vibrational energy and can achieve second-order accuracy in the fluid limit. • The efficiency of the USPBGK-DSMC hybrid method is excellent for the simulation of multi-scale hypersonic flows. Simulating hypersonic flow around a space vehicle is challenging because of the multiscale and nonequilibrium nature inherent in these flows. To effectively deal with such flows, a hybrid scheme combining the stochastic particle Bhatnagar-Gross-Krook (BGK) method with direct simulation Monte Carlo (DSMC) was developed recently, but only for monatomic gases (Fei et al. (2021) [29]). In this paper, the particle-particle hybrid method is extended to polyatomic gas flows. In the near continuum regime, employing the Ellipsoidal–Statistical BGK model proposed by Dauvois et al. (2021) [22] with discrete levels of vibrational energy, the stochastic particle BGK method for polyatomic gases is first established following the idea of the unified stochastic particle BGK (USP-BGK) scheme. It is proven to be of second-order accuracy in the fluid limit. After that, the USP-BGK scheme with rotational and vibrational energies is combined with DSMC to construct a hybrid scheme. The present hybrid scheme for polyatomic gases is validated with numerical tests of homogeneous relaxation, 1D shock structure and 2D hypersonic flows past a wedge and a cylinder. Compared to the other stochastic particle methods, the proposed hybrid scheme can achieve higher accuracy at a much lower computational cost. Therefore, it is a more efficient tool to study multiscale hypersonic flows. [ABSTRACT FROM AUTHOR]
- Subjects :
- *HYPERSONIC flow
*DISCRETE element method
*GASES
Subjects
Details
- Language :
- English
- ISSN :
- 00219991
- Volume :
- 471
- Database :
- Academic Search Index
- Journal :
- Journal of Computational Physics
- Publication Type :
- Academic Journal
- Accession number :
- 159710388
- Full Text :
- https://doi.org/10.1016/j.jcp.2022.111640