A scaling analysis for the evolution of small-scale turbulence eddies across premixed flames with implications on distributed combustion

A Computational Assessment of Combustion Submodels for Predictive Simulations of Pre-Chamber Combustion Engines

“…Note, however, that the flamelet assumption being overshadowed by the existence of the broken reaction zone, until today, remains debatable as widely reported in the literature [41,42]. The so-called distributed regime has not been observed either experimentally [42] or from DNS data [38,41].…”

“…As the jet issuing finishes, the trend monotonically decays as the small-scale turbulent structures are quickly dissipated and subsequently enter the corrugated flamelet regime. Note that as the MC composition becomes leaner (C5), a critical modeling implication arises, provided that the original G-Equation formulation has arguable validity beyond Karlovitz = 100 (𝐾𝑎 𝛿 = 1) [35,41,42]. Therefore, the predictive modeling of ultra-lean engine operation at high turbulent conditions should consider additional investigation on the validity of the original formulation and scaling arguments to predict combustion accurately at ultralean turbulent conditions.…”

“…Note, however, that the flamelet assumption being overshadowed by the existence of the broken reaction zone, until today, remains debatable as widely reported in the literature [41,42]. The so-called distributed regime has not been observed either experimentally [42] or from DNS data [38,41]. Recent works on active optical PC engines, despite the high turbulence levels, suggest it to be a flame dominant phenomenon [27,36,[43][44][45][46], provided the consistent attachment of the flame to the nozzle exit.…”