Development of a multi-component surrogate fuel model of marine diesel engine

Abstract

A fuel combustion mechanism was developed based on a multi-component surrogate fuel composed of n-tetradecane, toluene, methylcyclohexane (MCH), and ethanol, the four most common components of real diesel fuel. A decoupling methodology was used to develop the new surrogate fuel mechanism. The developed surrogate fuel model includes 97 species and 386 reactions. The accuracy of new mechanism was obtained by comparing with experiment data in shock tube, counterflow configuration and marine engine. The comparison results of the simulations and experiment were shown in this paper for ignition delay times (IDT). The deviations of calculations were within accepting error for n-tetradecane, toluene, methylcyclohexane, and ethanol respectively. The laminar flame speed was an important parameter to validate the accuracy of the mechanism. The variation trends were the same as the experimental results. The revised mechanism was coupled with computational fluid dynamic (CFD) to simulate the combustion of a marine engine. The influence of surrogate fuel components ratios were investigated based on the CFD model. The prediction results well coincided with the experimental results of in-cylinder pressure of the marine engine. However, the ratios of components in the surrogate fuel have large effect on the formation of NOx emissions, especially the content of n-tetradecane. The results suggest that the multi-component surrogate fuel mechanism is suitable for simulating the diesel combustion.