Performance and emission reduction of turbojet engine fueled with green fuel blends and nano-additives

Palm oil could be used as feedstock to produce green diesel to fulfil the worldwide requirement for a clean environment. The current study's purpose is to evaluate the effect of biodiesel with green fuel on the air-breathing engine performance and its exhaust emissions. GasTurb 13 is used to predict the performance of the selected engine (KingTech 180k turbojet engine) and its emission. The Pascal program was used to identify code files on the GasTurb 13 to predict the fuel emissions. In the experiment, PME blended with GD and Jet-A1 under three volume percentage ratios, namely GD20:PME30, GD30:PME20, and GD10:PME10. The simulation results were validated with the experimental data. In addition to that, nano-additives of CuO and GNP with 30 ppm were applied to the PME30. The purity, stability, and size of nanoparticles were checked using SEM and XRD characterization. The Differential Scanning Calorimetry (DSC) was applied to the sample to check the effect of adding the nanoparticles to the PME. Based on that, the results for physiochemical properties found that the density for GD10PME10 was 767.6 kg/m3 which is higher than the GD density value, while B25DEE5GNP30 gave 917.97 kg/m3 higher density compared to PME30. The viscosity for GD10PME10 decreased by 53.85% compared to PME, while the B20DEE10 decreased by 26.42% of the viscosity value compared to PME30. Regarding the heating value, GD increased by 0.74% of the HV compared to Jet-A1, while the GD10PME10 gave the highest HV value of the other blends which was 42.63 MJ/kg. The highest value of oxidation initiation temperature (OIT) achieved by B25GNP15CuO15 (OIT was 204.13˚C) compared to B25, while the OIT for B25GNP30 was 6.13% higher than B25. B25GNP30DEE5 gave 284.51 ˚C of OIT compared to other blends. The associated parameters with engine performance were thrust, specific fuel consumption, mass fuel flow, and exhaust gas temperature. The thrust value enhanced to 12.5% for GD10PME10 compared to Jet-A1 at 80k RPM, while the lowest TSFC value was 95 kg/kN.s given by GD10PME10 compared to Jet-A1. GD20PME30 achieved the lowest EGT value which was 550 ˚C at 80,000 RPM. Regarding emissions, the GD20PME30 generated the lowest value of CO emissions which was 150 ppm at 100k RPM, it gave 0.5% lowest value of CO2 emissions at 90k RPM compared to Jet-A1. But the Jet-A1 gave the lowest NOx emission which was 7.5 ppm at 120k RPM, while the GD10PME10 gave 12.5 ppm of NOx emission which is lower than other blends at max speed. About nanoparticles, B20DEE10GNP15CuO15 generated a 20% higher thrust value than PME30 at 120k RPM, also it gave 25 kg/kN.s of TSFC value which is lower than PME30 at 100k RPM. As to emissions, the CO emission for B25DEE5GNP30 was 12% lower than PME30 at low speed. The lowest NOx generated by B20DEE10GNP15CuO15 (4 ppm) at 25k RPM compared to PME30. Overall, the results indicated that adding nanoparticles and green fuel to biodiesel blends might improve the fuel’s physiochemical characteristics, which would ultimately enhance the fuel’s ability to burn more efficiently in aeroengines.