High-order adaptive time discretisation of one-dimensional low-Mach reacting flows: a case study of solid propellant combustion

TL;DR

This paper introduces a high-order adaptive time discretisation method for one-dimensional low-Mach reacting flows, specifically applied to solid propellant combustion, improving accuracy and efficiency in handling algebraic constraints.

Contribution

The paper develops a novel high-order adaptive time integration strategy using stiffly accurate Runge-Kutta methods for low-Mach reactive flows with algebraic constraints, demonstrating its effectiveness.

Findings

High-order methods achieve accurate variable predictions.

Proper handling of algebraic constraints enhances stability.

Method outperforms traditional schemes in efficiency and accuracy.

Abstract

Solving the reactive low-Mach Navier-Stokes equations with high-order adaptive methods in time is still a challenging problem, in particular due to the handling of the algebraic variables involved in the mass constraint. We focus on the one-dimensional configuration, where this challenge has long existed in the combustion community. We consider a model of solid propellant combustion, which possesses the characteristic difficulties encountered in the homogeneous or spray combustion cases, with the added complication of an active interface. The system obtained after semi-discretisation in space is shown to be differential-algebraic of index 1. A numerical strategy relying on stiffly accurate Runge-Kutta methods is introduced, with a specific discretisation of the algebraic constraints and time adaptation. High order is shown to be reached on all variables, while handling the constraints properly. Three challenging test cases are investigated: ignition, limit cycle, and unsteady response with detailed gas-phase kinetics. We show that the time integration method can greatly affect the ability to predict the dynamics of the system. The proposed numerical strategy exhibits high efficiency and accuracy for all cases compared to traditional schemes used in the combustion literature.