ICONE12-49388 A COMPUTATIONAL STUDY OF H 2 /N 2 JET DIFFUSION FLAME WITH RADIATION HEAT LOSS

ABSTRACT In this work simulation of a turbulent H 2 /N 2 jet diffusion flame with flamelet modeling has been presented. The favre averaged mixture fraction has been employed to model the combustion. Favre-averaged scalar quantities have been calculated from flamelet libraries by making use of a presumed Probability Density Function (PDF) method. To incorporate the effect of radiation heat transfer the combustion model has been extended using the concept of enthalpy defect. The predicted flame temperature profiles and chemical species concentrations with and without radiation heat loss are compared with experimental data. Predictions considering the radiation heat loss found to be in good agreement with temperature and chemical species measurements whereas the adiabatic model significantly overestimates temperatures in the downstream regions of flames where the significant heat loss occurs. This study shows that the combustion simulation using flamelet models considering radiation heat loss are effective for predicting the flow, temperature and chemical kinetics of H 2 /N 2 jet diffusion flame. To account for fluctuations of mixture fraction, its distribution is presumed to have the shape of a beta-function. Keywords: Diffusion flame, combustion, flamelet, radiation. INTRODUCTION In the recent years, there have been increasing interests in the use of computational modeling approaches in the design and performance prediction of combustion equipment. To obtain the reliable computational results, advanced combustion models need to be employed in the prediction of industry relevant flames where finite rate chemistry and non-equilibrium effects are often significant. One such approach of modeling turbulent non-premixed flames has been the use of flamelet model