  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.
