Evaluation of the wall heat flux in filtered premixed turbulent combustion

The paper focuses on modelling the heat flux through the isothermal wall boundary in premixed turbulent combustion. In a statistically stationary configuration, the distorted flames, advected by the incoming flow toward the wall, can be either head-on or entrained. The wall heat flux model with respect to the head-on and entrained parts are constructed differently to describe their distinct behaviours. In model validation, to exclude the interference from various inaccuracies, either numerically or experimentally, the filtered three-dimensional direct numerical simulation (DNS) fields are adopted as benchmark. Results justify that the newly proposed model is able to capture the wall heat flux statistics. The predictions are consistently satisfactory at different filter widths, performing clearly better than direct evaluation from the filtered temperature gradient and effective diffusivity. In addition, it is also straightforward to integrate this model together with existing flow solvers.