Effects of turbulent length scale on the bending effect of turbulent burning velocity in premixed turbulent combustion

The effects of turbulent integral length scale to flame thickness ratio on the bending effect burning velocity variation have been analysed based a three-dimensional Direct Numerical Simulation database statistically planar premixed flames with characteristic Lewis number unity propagating into forced unburned gas turbulence. It has demonstrated that Damköhler's first hypothesis remains valid for cases considered here and this utilised explain by analysing terms in generalised Flame Surface Density (FSD) transport equation. Under steady-state, surface area generation FSD tangential strain rate term equilibrium destruction curvature term. found influences relative contributions dilatation normal due rate. Similarly, arising from combined reaction diffusion component displacement speed, speed are affected ratio. propensity dominance strengthened decreasing strengthens increasing turbulence intensity it becomes major contributor large intensities. However, inner cut-off scale, which also limits maximum possible under stationary state, determines given is manifested area. At high intensities, levels off at smaller value ratio, consistent second explained scaling arguments utilising leading order balance between evolution intensities characterised Karlovitz small Damköhler values.