Premixed laminar C_1–C_2 stagnation flames: Experiments and simulations with detailed thermochemistry models

Abstract

A generally accepted mechanism for the combustion of C_1 and C_2 hydrocarbons is still elusive. This paper discusses a technique that can further validate and constrain such mechanisms, towards the development of a comprehensive model for small hydrocarbon combustion. The approach relies on detailed measurements of strained premixed flames in a jet-wall stagnation flow. This geometry yields a flow with boundary conditions that can be reliably specified, facilitating simulation and detailed comparisons with experiment. The diagnostics are optimized for accuracy, minimal flame disturbance, and rapid simultaneous recording of velocity and CH radical profiles. Flame simulations rely on a one-dimensional hydrodynamic model, a multi-component transport formulation, and several detailed chemistry models. Direct comparisons between experiment and simulation allow for an assessment of the various models employed. Experimental data for methane, ethane, and ethylene flames are compared to numerical simulations using several thermochemistry models. GRI-Mech 3.0, a C_3 model by Davis et al. (DLW99), and two versions of the San Diego mechanism are utilized. While GRI-Mech 3.0 and the DLW99 models accurately predict experiment in some cases, the 2005/03/10 revision of the San Diego mechanism is found to give the best overall agreement with experiment for methane, ethane, and ethylene flames.

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