Synergistic interactions of thermodiffusive instabilities and turbulence in lean hydrogen flames

Interactions of thermodiffusive instabilities and turbulence have been investigated by large-scale Direct Numerical Simulations (DNS) in this work. Two DNS turbulent premixed lean hydrogen/air flames performed a slot burner configuration at the same jet Reynolds number Re=11,000 Karlovitz Ka?15 using detailed chemical mechanism. Realistic transport models are employed one case, which features characteristic patterns thermodiffusively unstable flames, such as strong variations heat release super-adiabatic temperatures. In other diffusivities all species set equal to thermal diffusivity (unity Lewis numbers assumption) therefore suppressed. The local burning flame without is similar an unstretched laminar speed increases only due increase surface area agreement with previous studies for conditions. contrast, enhancement speed, not caused wrinkling, but greatly increased significant reaction rates. These equivalence ratio differential diffusion hydrogen. A comparison conditions reveals that rates significantly enhanced higher fluctuations curvature average strain rate induced turbulence. Thus, show synergistic effects, reflected fuel consumption per area. generation, governed tangential propagation curved segments, also different two cases. Most noteworthy, shown be determined smallest structures both unaffected instability However, lead production convexly featuring formation tongue-like penetrate into unburned gas, do exist unity numbers. This linked displacement flame, while absence instabilities, reduction increasing observed, leading destruction findings suggest sustained flows even interactions turbulence, needs accounted combustion models.