  The fractal scaling properties of turbulent premixed flame fronts have been
investigated and considered for modelling sub-grid scales in the
Large-Eddy-Simulation framework. Since the width of such thin reaction fronts
cannot be resolved into the coarse mesh of LES, the extent of wrinkled flame
surface contained in a volume is taken into account. The amount of unresolved
flame front is estimated via the "wrinkling facto" that depends on the
definition of a suitable fractal dimension and the scale at which the fractal
scaling is lost, the inner cut-off length {\epsilon}i. In this context, the
present study considers laboratory experiments and one-step reaction DNS of
turbulent premixed jet flames in different regimes of turbulent premixed
flames. Fractal dimension is found to be substantially constant and well below
that typical of passive scalar fronts. The inner cut-off length shows a clear
scaling with the dissipative scale of Kolmogorov for the regimes here
considered. These features have been exploited performing Large Eddy
Simulations. Good model performance has been found comparing the LES against a
corresponding DNS at moderate Reynolds number and experimental data at higher
Reynolds numbers.
