REDIM-PFDF Sub-grid Scale Combustion Modeling for Turbulent Partially-premixed Flame: Assessment of Combustion Modes

ABSTRACT

The focus of the present study is to evaluate the capability of reaction-diffusion manifold (REDIM) technique combined with presumed filtered density function (PFDF) method to calculate the important characteristics of turbulent partially-premixed flame with near-homogeneous inlets and inhomogeneous inlets. The REDIM approach reduces detailed chemical kinetics into two-dimensional chemistry table, where mass fractions of CO₂ and N₂ are used as reduced coordinates. The fluctuation of the scalars within the LES filter volume is modeled by the PFDF method. Higher shear generated turbulent intensity at the mixing layer of the fuel and air streams provides the near-homogeneous inlet conditions. The radial statistics analysis of the mixture fraction, temperature and species mass faction, and their comparison with the experimental data show the good performance of the REDIM-PFDF model. Scatter plots show the better agreement for the inhomogeneous case. The near-homogeneous case exhibits little discrepancy with the measured distribution because of the limited ability of the present model to capture local extinction effects. Flame index parameter identifies the multiple combustion modes present at different locations. This parameter shows the presence of premixed and diffusion dominated types of combustion near the main jet exit plane in the inhomogeneous and near-homogeneous cases, respectively.

KEYWORDS:

• Turbulent partially-premixed flame
• inhomogenous inlets
• reaction-diffusion manifold
• large eddy simulation

Acknowledgments

The support of Natural Science Foundation of China (NSFC) through project 91741117 and 51576092, the support of Natural Science Foundation of Jiangsu Province through project BK20151344, and the support of PAPD project funded by Jiangsu Higher Education Institution are gratefully acknowledged. The authors also thank Prof. A. Masri (The Sydney University) for providing the experimental results in electronic form and Prof. U. Maas (KIT, Germany) for providing the REDIM codes. The computation work is conducted in the HPC Center of Jiangsu University.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [91741117, 51576092]; Natural Science Foundation of Jiangsu Province [BK20151344]; Priority Academic Program Development of Jiangsu Higher Education Institutions.