Effects of radiation on the uncertainty of flame speed determination using spherically propagating flames with CO/CO2/H2O dilutions at elevated pressures

摘要: Abstract This work investigates numerically the effects of spectral dependent radiation on laminar flame speed determination using spherically propagating CH4/air and H2/air flames with CO/CO2/H2O dilutions at elevated pressures. Three different models, adiabatic, optically thin radiation, fitted statistically narrow band correlated k (FSNB-CK) are employed. The radiation-induced negative burned gas velocity, increased density ratio, chamber confinement induced flow compression investigated. It is found that compared to FSNB-CK model, adiabatic model over-predicts by 7% makes more significant under-prediction. Moreover, this discrepancy increases pressure. results also show a large velocity in radiative heat loss magnified further small combustion chamber. causes an under-estimation speed. ratio between unburned gases. use under-prediction Two corrections taking into account recommended for spherical mixtures. proposed study reduce uncertainty due radiation.