Effect of Aluminium Oxide Nano Additive on Diesel along with Gasoline Fumigation in Single Cylinder Diesel Engine

The present investigation mainly focuses on overcoming the limitations of gasoline fumigation (GF) in diesel engines by adding up nano fuel additives. Experiments are conducted to ascertain the engine working characteristics in a single-cylinder, four-stroke diesel engine using aluminum oxide (Al2O3) nano additives blended diesel as the main injection fuel along with GF as an inducted fuel. GF was achieved by controlling the electronic injector fitted at the intake manifold using open ECU software. Fuel map for GF was determined based on experiments with three divergent fumigation rates of 10%, 20%, and 30% based on energy consumption and optimized using the design of experiments. The optimization results showed 10% fumigation resulted in better performance and emission characteristics and it is selected for this present investigation. Fumigation results showed a decrease in brake thermal efficiency (BTE) at low and medium loads; increase at high loads.The two different mass fractions of 25 ppm and 50 ppm Al2O3 nano liquid are blended with diesel. Compared to GF with diesel, GF along with 25 and 50ppm Al2O3 nano additives blended diesel showed an increased BTE, maximum in-cylinder pressure, cumulative heat release rate; and reduced smoke opacity, CO, and unburned HC emissions at overall operating conditions. As the dosage level of Al2O3 increases from 25 to 50 ppm results in further enhancement of all working parameters except NOx emission. Finally, the addition of an Al2O3 nano additive is a suitable solution to overcome the limitations of GF in the CI engine.

Combustion Phasing Effect on Cycle Efficiency of a Diesel Engine Using Advanced Gasoline Fumigation

Advanced premixed compression ignition (CI) combustion using fumigation has been shown to yield significant improvements in indicated efficiency over traditional diesel combustion strategies while simultaneously reducing engine-out soot and NOx emissions. To better interpret these findings, a breakdown of the ways in which actual performance deviates from ideal engine cycles is helpful. Nonideal combustion phasing is one cause of such deviations. In this paper, the centroid of the calculated apparent heat release rate is used to estimate an adjusted maximum possible thermal efficiency based on constant volume combustion using an effective compression ratio concept. Using these metrics, experimental engine data are evaluated from a single cylinder direct-injection diesel engine operating in premixed CI mode enabled by gasoline fumigation and a diesel pilot injection. Indicated gross cycle efficiency was found to be higher for premixed fumigation compared with a conventional diesel condition at the same load. A key finding of the work is that the peak indicated cycle efficiency for fumigated premixed CI combustion occurs with combustion phased very close to top dead center. Shorter heat release duration and lower heat losses from the cylinder are thought to be the cause of differences in cycle efficiency between conventional combustion and premixed CI fumigation modes.