Hydrogen‐Assisted Combustion of Nanoparticles‐Enhanced <i>Abrus precatorius</i> Biodiesel‐Ethanol Blends in CI Engines

ABSTRACT An experimental investigation was conducted on a single‐cylinder variable compression ratio (VCR) diesel engine to evaluate a novel fuel formulation based on Abrus precatorius biodiesel. The research focuses on the synergistic impact of three additives: 10% ethanol, zinc oxide (ZnO) nanoparticles at concentrations of 50 and 75 ppm, and hydrogen gas enrichment at flow rates of 10 and 15 lpm. The engine was operated at compression ratios (CRs) of 16, 17, and 18 to comprehensively assess the effects on combustion characteristics such as cylinder pressure (CP) and net heat release rate (NHRR). The transition to a biodiesel‐ethanol blend initially yielded a modest reduction in combustion efficiency. This was effectively counteracted by the integration of ZnO nanoparticles, which significantly improved combustion metrics. The final enhancement was achieved through hydrogen supplementation, leading to the most robust combustion behavior observed in the study. Increasing the CR consistently amended both CP and NHRR for all tested fuels. Among the blends, B20 + E10 + NPs 75 ppm + Hydrogen (15 lpm) delivered the strongest combustion response. At CR18, this fuel achieved a peak CP of 77.6 bar and an NHRR of 74.5 J/deg, clearly outperforming the baseline diesel operation. These results identify the combination of higher compression ratio and the advanced biofuel‐nanoparticles‐hydrogen blend as the most effective configuration for enhancing combustion efficiency and thermal performance.