Laminar burning velocity of nitromethane + air flames: A comparison of flat and spherical flames

Laminar burning velocities, SL, of nitromethane and air flames at 1 atm and initial gas temperatures, T, of 338 K, 348 K, and 358 K were determined using the heat flux method. Measurements were performed in non-stretched flames, stabilized on a perforated plate burner under adiabatic conditions. The comparison of these new experimental data and recent literature results obtained in spherical flames at 423 K was guided by the analysis of the temperature dependence of SL using expression SL = SL0(T/T0)α, and also by kinetic modelling of premixed flames employing detailed mechanisms suggested in the literature. It was demonstrated that conventional recalculation of the flame front speed into the burning velocity using density ratio of the unburned and burned gases at equilibrium is inappropriate for spherical nitromethane flames. Both the laminar burning velocities and the power exponents, α, were compared with predictions of the kinetic mechanisms. Remaining discrepancies of the modelling and reconciled experimental data were highlighted.