A simplified unified wave-particle method for diatomic gases with rotational and vibrational non-equilibrium

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Yang, Sirui, Zhong, Chengwen, Ding, Ningchao, Cao, Junzhe, Zhang, He, Zhuo, Congshan, Liu, Sha
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912459553505280
author Yang, Sirui
Zhong, Chengwen
Ding, Ningchao
Cao, Junzhe
Zhang, He
Zhuo, Congshan
Liu, Sha
author_facet Yang, Sirui
Zhong, Chengwen
Ding, Ningchao
Cao, Junzhe
Zhang, He
Zhuo, Congshan
Liu, Sha
contents The hypersonic flow around near-space vehicles constitutes a multi-scale flow problem. Due to insufficient molecular collisions to achieve equilibrium, rarefied gas effects are present in the flow field. Thus, numerical methods capable of accurately resolving multi-scale flows are required. Furthermore, high-temperature gas effects in hypersonic flows mean vibrational excitation of polyatomic molecules. Consequently, numerical methods accounting for non-equilibrium in rotational and vibrational internal energy modes are required. This study derives a quantified model-competition (QMC) mechanism for diatomic gases with rotational and vibrational non-equilibrium, starting from integral solutions of kinetic model equations with rotational and vibrational energy. The QMC mechanism categorize collisional and free-transport particles in cell, applying computational weighting based on their local scale regimes. We developed a simplified unified wave-particle (SUWP) method for diatomic gases based on QMC mechanism. For the macroscopic of the method, a three-temperature model accounting for rotational and vibrational energy is incorporated into both the kinetic inviscid flux scheme and {Navier-Stokes} solvers. For the microscopic of the method, a collisionless DSMC solver is employed to resolve non-equilibrium flow physics. This work validates the proposed SUWP method with rotational and vibrational non-equilibrium through benchmark cases, including shock tube, shock structures, flow past a cylinder, Apollo 6 command module and space station Mir. Compared to the DSMC and deterministic methods, the SUWP method exhibits favorable computational efficiency while maintaining accuracy.
format Preprint
id arxiv_https___arxiv_org_abs_2507_00720
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A simplified unified wave-particle method for diatomic gases with rotational and vibrational non-equilibrium
Yang, Sirui
Zhong, Chengwen
Ding, Ningchao
Cao, Junzhe
Zhang, He
Zhuo, Congshan
Liu, Sha
Fluid Dynamics
Numerical Analysis
The hypersonic flow around near-space vehicles constitutes a multi-scale flow problem. Due to insufficient molecular collisions to achieve equilibrium, rarefied gas effects are present in the flow field. Thus, numerical methods capable of accurately resolving multi-scale flows are required. Furthermore, high-temperature gas effects in hypersonic flows mean vibrational excitation of polyatomic molecules. Consequently, numerical methods accounting for non-equilibrium in rotational and vibrational internal energy modes are required. This study derives a quantified model-competition (QMC) mechanism for diatomic gases with rotational and vibrational non-equilibrium, starting from integral solutions of kinetic model equations with rotational and vibrational energy. The QMC mechanism categorize collisional and free-transport particles in cell, applying computational weighting based on their local scale regimes. We developed a simplified unified wave-particle (SUWP) method for diatomic gases based on QMC mechanism. For the macroscopic of the method, a three-temperature model accounting for rotational and vibrational energy is incorporated into both the kinetic inviscid flux scheme and {Navier-Stokes} solvers. For the microscopic of the method, a collisionless DSMC solver is employed to resolve non-equilibrium flow physics. This work validates the proposed SUWP method with rotational and vibrational non-equilibrium through benchmark cases, including shock tube, shock structures, flow past a cylinder, Apollo 6 command module and space station Mir. Compared to the DSMC and deterministic methods, the SUWP method exhibits favorable computational efficiency while maintaining accuracy.
title A simplified unified wave-particle method for diatomic gases with rotational and vibrational non-equilibrium
topic Fluid Dynamics
Numerical Analysis
url https://arxiv.org/abs/2507.00720