Discrete Boltzmann modeling of detonation: based on the Shakhov model

TL;DR

This paper introduces a Discrete Boltzmann Model based on the Shakhov model for simulating detonation, allowing for flexible Prandtl numbers and detailed analysis of non-equilibrium effects beyond traditional models.

Contribution

The paper develops a new DBM based on the Shakhov model, extending the range of detonation phenomena that can be simulated with adjustable Prandtl numbers.

Findings

Peak heights of pressure, density, and velocity increase exponentially with Prandtl number.

Maximum stress within the wave peak varies parabolically with Prandtl number.

Peak heat flux decreases exponentially with both Prandtl and Mach numbers.

Abstract

A Discrete Boltzmann Model(DBM) based on the Shakhov model for detonation is proposed. Compared with the DBM based on the Bhatnagar-Gross-Krook (BGK) model, the current model has a flexible Prandtl numbers and consequently can be applied to a much wider range of detonation phenomena. Besides the Hydrodynamic Non-Equilibrium (HNE) behaviors usually investigated by the Navier-Stokes model, the most relevant Thermodynamic Non-Equilibrium (TNE) effects can be probed by the current model. The model is validated by some well-known benchmarks,and some steady and unsteady detonation processes are investigated. As for the von Neumann peak relative to the wave front, it is found that (i) (within the range of numerical experiments) the peak heights of pressure, density and flow velocity increase exponentially with the Prandtl number, the maximum stress increases parabolically with the Prandtl number, and the maximum heat flux decreases exponentially with the Prandtl number; (ii) the peak heights of pressure, density, temperature and flow velocity and the maximum stress within the peak are parabolically increase with the Mach number, the maximum heat flux decreases exponentially with the Mach number.