Abstract
The present work performs unsteady Reynolds-averaged Navier–Stokes
simulations to study the effect of turbulence–chemistry interaction
(TCI) on diesel spray flames. Three nozzle diameters (d0)
of 100, 180, and 363 μm are considered in the present study. The
Eulerian stochastic fields (ESF) method (with the TCI effect) and
well-stirred reactor (WSR) model (without the TCI effect) are considered
in the present work. The model evaluation is carried out for ambient
gas densities (ρam) of 30.0 and 58.5 kg/m3. The
ESF method is demonstrated to be able to reproduce the ignition delay
time (IDT) and lift-off length (LOL) with an improved accuracy than that
from the WSR method. Furthermore, TCI has relatively more influence on
LOL than on IDT. A normalized LOL (LOL*) is introduced, which considers
the effect of d0, and its subsequent effect on the fuel-richness in the rich premixed core region is analyzed. The RO2
distribution is less influenced by the TCI effect as ambient density
increases. The ESF model generally predicts a longer and wider CH2O distribution. The difference in the spatial distribution of CH2O between the ESF and WSR model diminishes as d0 increases. At ρam = 30.0 kg/m3, the ESF method results in a broader region of OH with lower peak OH values than in the WSR case. However, at ρam = 58.5 kg/m3, the variation of the peak OH value is less susceptible to the increase in d0 and the presence of the TCI model. Furthermore, the influence of TCI on the total OH mass decreases as d0
increases. The total NOx mass qualitatively follows the same trend as
the total OH mass. This present work clearly shows that the influence of
TCI on the global spray and combustion characteristics becomes less
prominent when d0 increases.
Original language | English |
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Journal | Energy Fuels |
Volume | 35 |
Issue number | 14 |
Pages (from-to) | 11457–11467 |
ISSN | 0887-0624 |
DOIs | |
Publication status | Published - 2021 |