This paper reports the development, validation, and application of the thermophysical and transport properties of coconut, palm, and soy methyl esters for fuel spray and combustion modeling under light-duty diesel engine conditions. The developed fuel library is implemented in an open-source CFD code. The fuel properties are validated for both constant volume combustion chamber and compression ignition (CI) engine operation at a wide range of conditions. Sensitivity analysis on the effects of individual fuel properties is also investigated under both conditions. The properties of interest for the study are density, vapor pressure, heat of vaporization, liquid heat capacity, vapor heat capacity, second-virial coefficient, liquid dynamic viscosity, vapor dynamic viscosity, liquid thermal conductivity, vapor thermal conductivity, surface tension, and vapor diffusivity. From these twelve physical and transport properties, only five have significant effects on fuel spray structure, combustion, and emission characteristics. These are vapor pressure, vapor diffusivity, surface tension, liquid density, and liquid dynamic viscosity. However, only vapor pressure and surface tension have the strongest influence on the mixture preparation process.

Graphene and its derivatives have drawn interest across many disciplines due to their remarkable properties. We investigated the influence of graphite oxide (GO), aluminum oxide (Al2O3), and cerium oxide (CeO2) nanoparticles at 0.1% and 0.01% dosing concentrations on the combustion characteristics of diesel fuel by using the single droplet combustion experiment. Shortened ignition delay (ID) by up to 46.5%, increased burn-rate constant (up to 29.4%), reduced peak temperature (up to 13.8%), and shortened burnout time (up to 19.2%) are observed when a GO nanoparticle is dosed in diesel fuel. These remarkable features may substantially improve the combustion efficiency and reduce harmful emissions in diesel engine applications.

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Summary Graphite oxide (GO) is an important member of the graphene family of carbon nanomaterials with remarkable physical, chemical, and thermal properties. We conducted an experimental investigation on the combustion characteristics of diesel and biodiesel droplets dosed with 0.1% GO. The fuels were tested by a single droplet combustion experiment in which the temporal variation in the burning behavior of a suspended droplet was captured using a high‐speed camera. Numerical analysis of the combustion data suggests that the addition of GO in both fuels resulted in shortened ignition delay (by up to 38.2%), increased burn‐rate constant (by up to 29.4%), lowered peak temperature (by up to 7.8%), and shortened burning period (by up to 11.6%). To illustrate, the burn‐rate constant increased from 0.68 to 0.88 mm2/second, and the burning period reduced from 2.7 to 2.2 seconds when GO was dosed in diesel. By contrast, the ignition delay and peak temperature both decreased from 1.6 to 1.4 seconds and 659 to 611 K, respectively, when GO was added in biodiesel. Our results suggest that the fuel additive–induced benefits could effectively reduce emissions and improve fuel consumption for diesel engine applications.

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