Methane/air premixed and partially premixed turbulent flames at high Reynolds number are characterized using Direct Numerical Simulations (DNS) with detailed chemistry in a spatially evolving slot Bunsen configuration.
Four simulations are performed at increasing Reynolds number up to 22400, defined based on the bulk velocity, slot width, and the reactants' properties, using 22 billion grid points, making it one of the largest simulations in turbulent combustion. The study covers different aspects of flame-turbulence interaction. It is found that the thickness of the reaction zone is similar to that of a laminar flame, while the preheat zone has a lower mean temperature gradient, indicating flame thickening. The characteristic length scales of turbulence are investigated and the effect of the Reynolds number on these quantities is assessed. The tangential rate of strain is responsible for the production of flame surface in the mean and surface destruction is due to the curvature term.
To perform these simulations, few preliminary steps were required: (i) a skeletal mechanism was developed reducing GRI-3.0; (ii) a convergence study is performed to select the proper spatial and temporal discretization and (iii) simulations of fully developed turbulent channel flows are performed to generate the inlet conditions of the jet.
7/02/2019
Il Dr.Stefano Luca (KAUST, SA) terrà un seminario il giorno 7 Febbraio 2019, alle ore 12:00 in sala teleconferenze del DIMA