Large Eddy Simulation of a Turbulent Lifted Flame via Rate-Controlled Constrained Equilibrium
نویسنده
چکیده
via Rate-Controlled Constrained Equilibrium S. Rigopoulos , S. Navarro-Martinez , 1 School of Mechanical, Aerospace and Civil Engineering, University of Manchester, UK 2 Department of Mechanical Engineering, Imperial College London, UK Abstract The objective of this paper is the simulation of a turbulent lifted flame via employing Rate-Controlled Constrained Equilibrium (RCCE) for the chemistry and a Large-Eddy-Simulation (LES)-based Conditional Moment Closure (CMC) approach for the flow field and turbulence-chemistry interaction modeling. RCCE is a systematic method for mechanism reduction, based on the concept that certain species characterized by faster time scales are in a constrained equilibrium state, determined by the concentration of the species controlled by the chemical kinetics. A general system of implicit differential equations can be derived, regardless of the selection of fast and slow species. The RCCE ODEs can then be coupled with a RANS or LES-based approach for turbulent flame modeling. The flame simulated here is a turbulent lifted flame, the “Cabra” flame consisting of a jet of methane/air issuing into a vitiated co-flow, and it presents all characteristics of auto-ignition coupled with turbulent stabilization. Results show good agreement with experiments, the discrepancies being mainly due to the use of a coarse mesh.
منابع مشابه
Large-Eddy Simulation of a Turbulent Lifted Flame in a Vitiated Co-Flow
Large-eddy simulation (LES) of a lifted flame in a vitiated co-flow has been performed using an unsteady flamelet/progress variable (UFPV) model. This model is an extension to the steady flamelet/progress variable approach, and describes the transient autoignition process of the lifted flame through the unsteady flamelet model. The particular advantage of this model is that it eliminates the fl...
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