The influence of the evaporation model on ethanol turbulent jet flame simulation

Abstract

High-precision numerical simulation of aero-engine combustors requires a suitable evaporation model. At present, quantitative research on the effects of the evaporation model on two-phase turbulence combustion simulation is insufficient. Ethanol has a higher latent heat of evaporation than other fuels like acetone and aero kerosene, thus it is especially sensitive to the evaporation model. This paper uses LES to simulate turbulence in an aero-engine combustor, and TPDF to describe the interaction between turbulence and chemical reactions. Numerical simulation results of the Abramzon-Sirignano (A-S), Spalding, and thick exchange layer (NC-TEL) evaporation models for high-Reynolds number ethanol combustion in two-phase turbulent jet flames are analyzed and compared with experimental data. Results suggest that per unit time, the A-S evaporation model has the largest evaporation mass, followed by the NC-TEL evaporation model, while the Spalding evaporation model has the smallest evaporation mass. Through quantitative analysis of the different evaporation models’ influence on temperature, mixture fraction, and liquid phase distribution, it is found that the A-S evaporation model fits the experimental data better in the central region of jet flame but has worse performance in the other flame regions. The simulation result of the Spalding model is good in the X/D = 10 section, and that of the NC-TEL model shows the best result at X/D > 10 sections and in the outer regions of the jet flame. The maximum difference between the NC-TEL model results and the experimental data was 21.856 % in liquid phase velocity. Hence, the NC-TEL model has the best simulation performance.