A Robust Reacting Flow Solver with Computational Diagnostics Based on OpenFOAM and Cantera

Hongyuan Zhang,Suo Yang,Dezhi Zhou

doi:10.3390/aerospace9020102

Abstract

In this study, we developed a new reacting flow solver based on OpenFOAM (OF) and Cantera, with the capabilities of (i) dealing with detailed species transport and chemistry, (ii) integration using a well-balanced splitting scheme, and (iii) two advanced computational diagnostic methods. First of all, a flaw of the original OF chemistry model to deal with pressure-dependent reactions is fixed. This solver then couples Cantera with OF so that the robust chemistry reader, chemical reaction rate calculations, ordinary differential equations (ODEs) solver, and species transport properties handled by Cantera can be accessed by OF. In this way, two transport models (mixture-averaged and constant Lewis number models) are implemented in the coupled solver. Finally, both the Strang splitting scheme and a well-balanced splitting scheme are implemented in this solver. The newly added features are then assessed and validated via a series of auto-ignition tests, a perfectly stirred reactor, a 1D unstretched laminar premixed flame, a 2D counter-flow laminar diffusion flame, and a 3D turbulent partially premixed flame (Sandia Flame D). It is shown that the well-balanced property is crucial for splitting schemes to accurately capture the ignition and extinction events. To facilitate the understanding on combustion modes and complex chemistry in large scale simulations, two computational diagnostic methods (conservative chemical explosive mode analysis, CCEMA, and global pathway analysis, GPA) are subsequently implemented in the current framework and used to study Sandia Flame D for the first time. It is shown that these two diagnostic methods can extract the flame structure, combustion modes, and controlling global reaction pathways from the simulation data.

Highlights

Published: 14 February 2022High-fidelity reacting flow simulations are becoming more and more important nowadays with the increasing demand for designing clean and efficient energy conversion and propulsion technologies
GRI-Mech 3.0 mechanism [37] was used, and the SEULEX ordinary differential equations (ODEs) solver was employed to integrate the chemistry except for the last case which applies the CVODES solver for comparison
The current work extends the capability of OpenFOAM (OF) dealing with chemical mechanisms with PLOG reaction types, as well as in integrating stiff chemistry with the widely used CVODES solver

Summary

Introduction

Published: 14 February 2022High-fidelity reacting flow simulations are becoming more and more important nowadays with the increasing demand for designing clean and efficient energy conversion and propulsion technologies. The combustion processes in these technologies involve complex multi-component mixtures. Robust reacting flow solvers with the capability to simulate the physical and chemical processes with detailed chemistry and transport properties for a large number of chemical species are fundamentally needed. It is well-known that the combustion processes in practical engines involve turbulence, and turbulence–chemistry interaction needs to be accurately understood [1]. Within OpenFOAM (OF) [2] computational fluid dynamics (CFD) platform, the reactingFoam solver contains multi-species finite-rate chemistry and thermodynamics, together with plenty of options for turbulence and turbulent combustion models, and is widely used in the combustion community [3,4]. The underlying reason is due to the Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations

Objectives

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Conclusion