Numerical Analysis of Adiabatic Flame Temperature for Kerosene-Ethanol Blends Using the Major-Minor Species Model

Abstract

The adiabatic flame temperature (Tad) of alternative aviation and industrial fuels is investigated numerically over a broad range of equivalence ratios (φ) from 0.5 to 1.5. This study assesses the thermodynamic and thermal properties of liquid kerosene blended with bio-derived ethanol at concentrations of 5%, 10%, and 15% by mass using the "Major-Minor Species Model". By classifying the combustion products into major species (CO2, H2O, N2, O2, CO, H2) and minor dissociation radicals (OH, O, H, NO), the model simplifies complex chemical equilibrium and enables high-accuracy temperature predictions with low computational overhead. The results demonstrate that the adiabatic flame temperature peaks slightly on the rich side of the stoichiometric point (φ = 1.05), reaching approximately 2262 K for pure kerosene and dropping progressively by 12 K to 35 K as ethanol blending increases to 15% (E15). This decrease is primarily attributed to the lower heating value (LHV) of ethanol. The inclusion of minor species dissociation was found to be crucial for accuracy, preventing temperature overpredictions by up to 1.8% near stoichiometric conditions. The results show that the Major-Minor model is a reliable tool for forecasting product compositions and combustion temperatures, offering crucial information for the development of high-efficiency, low-emission blended fuel energy conversion systems.