Development of a new reduced n-pentane mechanism with NOX for combustion simulation at atmospheric pressure

Abstract

Air-light hydrocarbon mixing gas is a new type of fuel with great potential, and its key component is n-pentane. In this study, a reduced n-pentane mechanism with NOX is developed for combustion simulation at atmospheric pressure, including 81 species and 348 elementary reactions. First, the dominant species and reactions for n-pentane combustion are recognized by the reaction pathway analysis based on the detailed mechanism. Then, a novel multistep reduction strategy with intersection thought is proposed to reduce the detailed mechanism of n-pentane. Ignition delay time and laminar flame speed are separately selected as the target parameters for validation. The two reduced mechanisms are developed by using the directed relation graphs (DRG) method, the directed relation graphs with error propagation (DRGEP) method, and the full species sensitivity analysis (FSSA) method. Species in the intersection mechanism of the above two mechanisms obtained with multistep reduction are treated as important species. Sensitivity analysis (SA) is further performed to remove the uncertain species, combined with the result of reaction pathway analysis, a reduced n-pentane mechanism including 77 species and 336 reactions is obtained. On this basis, a reduced NOX mechanism (4 species and 12 reactions) is incorporated. Then, the key kinetic parameters of the mechanism are optimized and adjusted according to the results of brute force sensitivity analysis. Finally, the proposed mechanism is validated by using the related data of ignition delay times, laminar flame speeds, premixed flame species profiles, and jet-stirred reactor (JSR) species profiles. The results indicate that the proposed mechanism shows good model performance. This study can provide significant assistance for subsequent research on air-light hydrocarbon mixing gas.