Numerical and experimental investigation of the influence of various metal-oxide-based nanoparticles on performance, combustion, and emissions of CI engine fuelled with tamarind seed oil methyl ester

The present study aims to experimentally and numerically investigate diesel engine's combustion, performance, and exhaust emission characteristics fuelled with tamarind seed oil methyl ester (TSOME) and nanoparticles as fuel additives. The Diesel-RK, a complete thermodynamic cycle engine analysis tool, is employed to assess the engine characteristics. Cerium Oxide (CeO2) and Aluminium Oxide (Al2O3) nanoparticles are introduced as additives and dispersed in pure TSOME at a concentration of 30 ppm to obtain TSOME + CeO2 and TSOME + Al2O3 blends correspondingly. The tests are conducted when the engine is loaded from 0 to 100% with intervals of 25%. The research reveals that incorporating CeO2 and Al2O3 improves the BTE by 17-18% compared to that of TSOME. TSOME + CeO2 and TSOME + Al2O3 substantially decreased CO2, HC, and smoke emissions compared to those of conventional diesel fuel. Furthermore, when CeO2 and Al2O3 nanoparticles are added into the TSOME fuel, oxides of nitrogen emissions are mitigated by 6-7% compared to TSOME by reducing the fuel consumption. Also, the addition of nanoparticles led to an improvement in combustion characteristics compared to pure TSOME due to the high catalyst role of nanoparticles, which accelerate the chemical reactions during the combustion cycle. Furthermore, the nanoparticles-added test fuels have generally presented the competitive results with each other, but the CeO2 nanoparticle presented slightly better results in terms of exhaust emissions, while Al2O3 added test fuel gave slightly better results in terms of engine performance. Finally, the results of this research show that metal oxide-based nanoparticles such as CeO2 and Al2O3 as a fuel additive can improve the characteristics of diesel engines fuelled by biofuels.