LES of the Sandia Flame D Using an FPV Combustion Model

TL;DR

This study compares large eddy simulations and RANS models using a flamelet progress variable approach to accurately predict turbulent combustion in the Sandia D flame, highlighting the advantages of LES with filtered approaches.

Contribution

It demonstrates that LES with a filtered approach provides more accurate predictions of turbulent combustion than RANS, even on coarser grids, for the Sandia D flame case.

Findings

LES with filtered approach outperforms RANS in accuracy.

LES recovers inlet discrepancies better along the flow.

Filtered approach improves prediction accuracy at lower computational costs.

Abstract

The simulation of turbulent combustion phenomena is still an open problem in modern fluid dynamics. Considering the economical importance of hydrocarbon combustion in energy production processes, it is evident the need of an accurate tool with a relatively low computational cost for the prediction of this kind of reacting flows. In the present work, a comparative study is carried out among large eddy simulations, performed with various grid resolutions, a Reynolds averaged Navier-Stokes simulation, and experimental data concerning the well-known Sandia D flame test case. In all the simulations, a flamelet progress variable model has been employed using various hypotheses for the joint probability density function closure. The filtered approach proved to be more accurate than the averaged one, even for the coarser grid used in this work. In fact both approaches have shown poorly accurate predictions in the first part of the combustion chamber, but only by the large eddy simulation one is capable to recover the inlet discrepancies with respect to the experimental data going along the streamwise direction.