Modeling nonadiabatic turbulent premixed reactive flows including tabulated chemistry

A two-scalar probability density function (PDF) is used to evaluate the mean chemical rate in turbulent combustion. This presumed PDF is based on an original closure model which has previously been validated for adiabatic partially premixed combustion. This model is now extended to nonadiabatic premixed combustion in a turbulent reactive flow and only requires transport equations for means and variances of two independent thermodynamical quantities, i.e., fuel mass fraction and enthalpy. Numerical simulations of a turbulent propane/air flame stabilized in the vicinity of recirculation kernels generated by a sudden expansion are performed. Heat losses at the combustion chamber walls are incorporated and depend on the wall material thermal characteristics. Two chemical mechanisms are investigated: (i) a global one-step reaction following an Arrhenius law and (ii) a tabulated chemistry (FPI technique) predicting intermediate species (carbon monoxide, OH and CH radicals, etc.). Numerical simulations on the mean velocity and temperature fields are compared to experimental data. In particular, the capability of the model to predict the temperature field, a quantity depending on both fuel mass fraction and enthalpy, is clearly demonstrated.