The prediction of the auto-ignition sensitivity to the temperature in new engine combustors is a challenge
in the community of numerical combustion. This paper is devoted to the modeling of temperature
fluctuations for the simulation of reactive flows in real internal engine configurations. It aims at validating
the temperature fluctuation equation model Truffin and Benkenida and its coupling with the ECFM3Z
combustion model of Colin and Benkenida. Especially, this study focuses on the auto-ignition process
which is described by the TKI (Tabulated Kinetics for Ignition) model of Knop and Jay. TKI is based on
a tabulation method for reaction rates and its coupling with the temperature fluctuation is achieved
through a presumed PDF approach. The integral limits for the PDF integration are determined locally
through transport equations with appropriate closures on isothermal walls. The resulting model, called
TKI–tT, is applied on Homogeneous Charge Compression Ignition (HCCI) combustion mode engine for
which the only source of thermal stratification is wall heat loss. Comparisons with experiments demonstrate
the impact of temperature fluctuations and the ability of the model to improve the prediction of
the auto-ignition model.