Reactive mixtures with the lattice Boltzmann model

TL;DR

This paper introduces a novel lattice Boltzmann model for reactive gas mixtures that accurately captures chemical reactions, heat effects, and species interactions, validated through benchmarks like flame speed and expansion.

Contribution

It extends existing lattice Boltzmann models to include chemical reactions and heat effects, ensuring thermodynamic consistency without ad-hoc source terms.

Findings

Successfully models reactive flows with chemical reactions

Accurately predicts laminar burning speeds and flame expansion

Maintains thermodynamic consistency in simulations

Abstract

A new lattice Boltzmann model for reactive ideal gas mixtures is presented. The model is an extension to reactive flows of the recently proposed multi-component lattice Boltzmann model for compressible ideal gas mixtures with Stefan-Maxwell diffusion for species interaction. First, the kinetic model for the Stefan--Maxwell diffusion is enhanced to accommodate a source term accounting the change of the mixture composition due to chemical reaction. Second, by including the heat of formation in the energy equation, the thermodynamic consistency of the underlying compressible lattice Boltzmann model for momentum and energy allows a realization of the energy and temperature change due to chemical reactions. This obviates the need for ad-hoc modelling with source terms for temperature or heat. Both parts remain consistently coupled through mixture composition, momentum, pressure, energy and enthalpy. The proposed model uses the standard three-dimensional lattices and is validated with a set of benchmarks including laminar burning speed in the hydrogen-air mixture and circular expanding premixed flame.