Discrete Boltzmann modeling of high-speed compressible flows with various depths of non-equilibrium

Abstract

The non-equilibrium high-speed compressible flows present wealthy applications in engineering and science. With the deepening of Thermodynamic Non-Equilibrium (TNE), higher-order non-conserved kinetic moments of the distribution function are needed to capture the main feature of the flow state and evolution process. Based on the ellipsoidal statistical Bhatnagar-Gross-Krook model, Discrete Boltzmann Models (DBMs) that consider various orders (from the first up to the sixth order) of TNE effects are developed to study flows in various depths of TNE. Specifically, at first, two types of one-dimensional Riemann problems and a Couette flow are used to show the model's capability to capture large flow structures with zero-order and first-order TNE effects, respectively. Then, a shock wave structure given by Direct simulation Monte Carlo is used to verify the model's capability to capture fine structures at the level of mean free path of molecules. Further, we focus on the TNE degree of two colliding fluids. A five-component vector ${\mathbf{S}}_{TNE}=(\tau ,\Delta \mathbf{u},\Delta T,{\mathbf{\Delta }}_2^{\ast },{\mathbf{\Delta }}_{3,1}^{\ast })$ is introduced to roughly characterize the TNE degree. It is found that the TNE strengths obtained from various perspectives are different. These findings demonstrate that the inadequacy of focusing only on the few kinetic moments appearing in Navier-Stokes increases with the degree of discreteness and deviation from thermodynamic equilibrium. Finally, a two-dimensional free jet is simulated to indicate that, to obtain satisfying hydrodynamic quantities, the DBM should include at least up to the third-order TNE effects.

This manuscript has been published in POF, please cite it as: Phys. Fluids 34, 086104 (2022). The website of this article is https://doi.org/10.1063/5.0100873

References in corpus (14)

• Modeling realistic multiphase flows using a non-orthogonal multiple-relaxation-time lattice Boltzmann method
• Discrete Boltzmann multi-scale modeling of non-equilibrium multiphase flows
• Multiple-relaxation-time lattice Boltzmann kinetic model for combustion
• A multi-component discrete Boltzmann model for nonequilibrium reactive flows
• Morphological and non-equilibrium analysis of coupled Rayleigh-Taylor-Kelvin-Helmholtz instability
• Multiple-relaxation-time discrete Boltzmann modeling of multicomponent mixture with nonequilibrium effects
• Late-time description of immiscible Rayleigh-Taylor instability: A lattice Boltzmann study
• Kinetic modeling of multiphase flow based on simplified Enskog equation
• Discrete Boltzmann Modeling of Plasma Shock Wave
• Discrete Boltzmann modeling of Rayleigh-Taylor instability: effects of interfacial tension, viscosity and heat conductivity
• Nonequilibrium effects of reactive flow based on gas kinetic theory
• Rayleigh-Taylor instability under multi-mode perturbation: discrete Boltzmann modeling with tracers
• Two-fluid discrete Boltzmann model for compressible flows: based on Ellipsoidal Statistical Bhatnagar-Gross-Krook
• Discrete Boltzmann modeling of detonation: based on the Shakhov model

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