Combustion characteristics of a diesel engine running with Mandarin essential oil -diesel mixtures and propanol additive under different exhaust gas recirculation: Experimental investigation and numerical simulation

Essential oils are promising sources for producing alternative fuel, owing to their sustainability and obtainability. Thus, this article aimed to investigate the impacts of introducing mandarin-essential oil with diesel fuel on the engine performance operated under numerous loads and a fixed speed of 1500 rpm. There are two mixing ratios of 10% and 20% mandarin essential oil and 80%, and 90% diesel fuel, which are signified as MO10 and MO20, respectively. Then, the DieselRK model is used to predict the influence of adding propanol (10% by volume) to (90%) mandarin-essential oil with applying EGR of 1%, 3% and 5% approach. The Egyptian-mandarin-essential oil is characterized using gas-chromatography-mass-spectrometry analysis, and its physical properties are measured corresponding to ASTM standard. The experimental findings demonstrate that the cylinder pressure and HRR are decreased by 3% and 2.5%, respectively, with the supplement of mandarin-essential-oil with diesel fuel. The CO, UHC, and smoke opacity are lowered by (17%, 30%), (20%, 40%), and (27%, 44%) for MO10 and MO20 combinations, compared with the base fuel, while the NOx intensity is inflated by 25% and 45% respectively. Specific fuel consumption is decreased by 5% and 22% for MO10 and MO20 blends, respectively. The validation indicates a decent acceptance among the experimental and simulation data. The simulation findings demonstrate that the EGR approach effectively lowers the NOx level with the minimum effect on the soot level.