This paper presents new tabulated approaches for turbulent combustion and pollutants for the simulation of auto-igniting non-premixed flames like encountered in Diesel engines or turbomachines. The Approximated Diffusion Flame Presumed Conditional Moment (ADF-PCM) combustion model is based on the formalism proposed by (Gicquel 2000, Vervisch et al., 2004) for the FPI-PCM model. In the present ADF-PCM approach, homogeneous auto-igniting reactor calculations with complex chemistry are used to resolve an approximate flamelet equation (Peters, 2000). This allows to reproduce both the auto-ignition of a non-premixed mixture and the steady flamelet structure (Michel et al., 2008). The nitric oxide formation cannot be described by the main combustion table because the related characteristic time-scales are much larger than the fuel oxidation time-scale. Therefore, a new thermal NO reaction rate expression is proposed, based on the NO equilibrium mass fraction and characteristic reaction time taken from homogeneous reactor calculations. Its coupling with the ADF-PCM flamelet equation finally leads to a mean NO reaction rate model. The resulting tabulated combustion model including NO is validated on the (Cabra et al., 2005) experiment.
展开▼
