Experimental and Numerical Study of PMMA Combustion in Counterflow Configuration

PMMA burning in counterflow has been studied experimentally and numerically. Thermal and chemical structure including concentrations of main species, i.e. ММА, O2, N2, CO2, CO and H2O, as well as an integral parameter (mass loss rate of a sample) were measured. The mathematical model is set in a coupled gas–solid formulation to resolve heat and mass transfer between gas-phase flame and thermally degrading solid combustible. Gas-phase combustion was modeled in the open-source Cantera software in a one-dimensional counterflow flame configuration. Governing equations of solid fuel was solved in an in-house code in two-dimensional formulation. Two chemical mechanisms of MMA oxidation (skeletal and detailed) were employed to resolve gas-phase combustion. Two sets of parameters of PMMA pyrolysis reaction were investigated. Gas phase temperature distribution was experimentally shown to be almost uniform in the direction parallel to the sample's burning surface in the area up to 4 mm from the sample's axis. The best agreement for macroscopic parameter, mass loss rate, was obtained by employing Lengelle pyrolysis kinetics, which is within 10 %. Total heat flux from gas-phase flame to the solid sample is about 23 kW/m2. Both gas-phase combustion mechanisms overpredict maximal temperature in flame by about 200 °C.