OpenFOAM based conditional moment closure (CMC) model for solving non-premixed turbulent combustion: Integration and validation

Abstract

This article presents a direct integration of conditional moment closure (CMC), an advanced combustion model with a computational fluid dynamics (CFD) package, OpenFOAM (Open-source Field Operation And Manipulation) to solve non-premixed turbulent combustion. Earlier our group (Roy and Sreedhara, 2016) had coupled CMC code with FLUENT to model non-premixed turbulent combustion, but it was through manual two-way coupling method where CFD and CMC codes were sequentially solved one after the other until the steady state is reached. The extensible and flexible framework of OpenFOAM encouraged us to build a CFD-CMC solver called cmcFoam. This fully-coupled solver solves CMC equations internally in OpenFOAM along with flow-field equations. Major advantages of this solver are (1) it is built in the open-source framework, (2) it can predict the transient behavior of flames, and (3) one can benefit from all features of OpenFOAM. The validity of the proposed solver has been thoroughly demonstrated by accurately predicting experimental data published for the Sandia syngas (CO/H2/N2) flame. Two-dimensional axisymmetric simulations were performed with a modified k-ε turbulence model and using a chemical kinetic scheme having 21 species and 84 chemical reactions (DRM 19). Results predicted by the solver showed an excellent agreement with the published data, both in mixture fraction and physical space. This benchmarked coupled code may be useful to analyze fairly complex industrial problems.