Thermophysical properties, combustion, performance, and emission analysis of ZnO, TiO₂, and GNP-enhanced WCOME–diesel–DGM triple fuel blends in a CRDI diesel engine

The continuous utilization of non-renewable/conventional fuels for different fields of applications creates intense demand, increasing costs, and hazardous exhaust gases, which cause depletion of these products from the Earth’s source. This scenario urges researchers to find alternative fuels. But, the drawbacks of the biodiesel fuel blends could be recovered by the employment of alcohol and nano additives. The present study aims to investigate the performance, combustion, and emission parameters of a twin cylinder, 4-stroke, Common Rail Direct Injection (CRDI), Compression Ignition (CI) engine using Ternary Fuel (TF (20% of Waste Cooking Oil Methyl Ester (WCOME)-70% Vol. of Diesel (D100) -10% Vol. of Diethylene Glycol Dimethyl Ether (DGM)) with different nanoparticles (NPs). The NPs are dispersed in TF with the aid of QPAN80 surfactant at a ratio of 1:4 using an ultrasonicator (Hielscher ultrasonicator, at 40 kHz and 160 W for 20 min). The prepared NPs blended TF mixtures are observed to be stable and consistent in 3 weeks test, evidenced by UV-vis spectroscopy. Initially, D100 fuel is tested on a 2-cylinder, CRDI, diesel engine. Then, the remaining fuel mixtures are tested under different loads. The performance outcomes are noticed to be improved (Brake Thermal Efficiency (BTE) is increased by 11.18%, and Brake Specific Fuel Consumption (BSFC) is lowered by 14.19% than that of D100 at higher load for the TF+GNP50 sample. Further, the combustion parameters, including Cylinder Pressure (CP) and Net Heat Release Rate (NHRR), are enhanced by 29.78% and 9.9% over the D100 sample. While ID is decreased by 12.58% at higher load as compared to the WCO20 sample. Moreover, the emissions such as Carbon monoxide (CO), Carbon dioxide (CO 2 ), Hydrocarbons (HC), and Nitrogen Oxide (NOx) are significantly reduced by 8.62, 17.43, 8.93, and 7.88% respectively as correlated to D100 fuel for the same sample at higher load. The outcomes of this study reveal that the TF+GNP50 sample enhanced performance, combustion, and emission parameters of a diesel engine without any modifications.