Hydrogen‐Enriched Direct Injection Diesel Engine Performance, Emission, Combustion, and Sensitivity Analysis Using Ethanol–Nahar Biodiesel Blends

Energy is essential for performing work and vital for advancing and evolving humanity. However, conventional energy sources are nonrenewable, have finite reserves, and are geographically restricted. Therefore, it is imperative to explore alternative energy sources that are renewable, locally accessible, and produce fewer emissions. This experimental study emphasizes the advantages of incorporating hydrogen into a compression ignition (CI) engine running on a blend of ethanol and Nahar oil biodiesel, particularly regarding performance, emissions, combustion, and sensitivity characteristics. A single‐cylinder direct‐injection diesel engine was tested under loads ranging from 20% to 100% at a constant speed of 1500 rpm (±5 rpm). Two different proportioned blends of diesel Nahar oil methyl ester (DNOME)–ethanol, DNOME90E10 (contains 90% diesel, 10% NOME, and 10% ethanol), and DNOME80E20 (80% diesel, 20% NOME, and 20% ethanol) are tested along with three different hydrogen injection durations: 1000, 2000, and 3000 µs (DNOME90E10H1, DNOME90E10H2, and DNOME90E10H3), respectively. A small add blend of hydrogen, especially at an injection duration of 2000 µs enhances brake thermal efficiency (BTHE) by 5.43% over normal biodiesel‐ethanol blend, and a 2.42% reduction in brake specific fuel consumption (BSFC) compared to the base DNOME90E10 blend at full load. It also showed reduced emissions of nitrogen oxide (NO x ) (4.23%), hydrocarbon (HC, 3.45%), and carbon monoxide (CO) (19.36%) at full load condition. An improved in‐cylinder pressure and heat release characteristics is shown with DNOME90E10H2 producing a peak cylinder pressure of ~73 bar and a maximum heat release rate of 52 J/°CA, indicating enhanced combustion efficiency. In sensitivity analysis, a heat map study shows that the hydrogen mixes with DNOME90E10 as lower emissions compared to pure diesel and DNOME80E20. The results indicate that the DNOME90E10H2 configuration shows the best setup for achieving efficient performance in CI engines while significantly lowering emissions.