Assessment of diesel engine thermo-characteristics working with hybrid fuel blends

The objective of this study is to examine the impact of multifuel blends on combustion parameters of single-cylinder four-stroke direct injection diesel engines. Engine characteristics (performance, combustion, and emissions) are scanned under the following scenario: initially powered by regular diesel (DF), then 20% biodiesel derived from spirulina green algae. Afterward, 40% water ammonia solution (25% NH3) is used, followed by a hybrid blend (40% DF + 20% biodiesel + 40% NH4OH). Simulations are performed using Diesel-RK software. In contrast to diesel and biodiesel, aqueous ammonia solution has a longer delay period due to lower cetane number. In comparison with diesel, the Sauter mean diameter (SMD) is increased by 1.6%, 3.8% for biodiesel and NH4OH, while it is decreased by 13% for hybrid fuel. Peak values of pressure and temperature are reduced. All fuel blends under consideration had significant reductions in nitrogen oxides (NOx) and Bosch smoke number (BSN). Hybrid fuel reduced NOx emissions by 37% and BSN by 53.5% compared to DF. Compared to DF, there was a slight increase in brake-specific fuel consumption (BSFC) coupled with a decrease in thermal brake efficiency (BTE). The optimal fuel compromise for dual-fuel diesel engines is the usage of biodiesel and aqueous ammonia together (hybrid mode). There is an excellent convergence between these outcomes and those of other scientists.