Experimental and Numerical Assessment of Engine Performance Using Cyclopentanone and Anisole as Neat Fuels and as Blends with Gasoline 2023-32-0050

The dilution of the cylinder charge using excess air enables both an increase in the net indicated efficiency and a decrease in the engine-out emissions of nitrogen oxides. The maximum excess air dilution capability in a spark-ignition engine depends on both the ignition of the charge and the flame propagation. These two aspects can be influenced by the fuel properties, which draw attention to the laminar burning velocity of alternative fuels to extend the lean limit. Cyclopentanone and anisole show promising values regarding the laminar burning velocity. However, there is a lack of engine investigations using these two fuels. To this end, both fuels were assessed in an engine application using experimental and numerical investigations. Cyclopentanone and anisole were investigated as neat components and as mixtures with conventional gasoline fuel, resulting in seven investigated fuels. The engine performances of all seven fuels were assessed in variations of the excess air ratio at net indicated mean effective pressures of 6 bar and 15 bar at an engine speed of 2000 1/min using a spark-ignition single-cylinder engine for passenger car applications. Moreover, numerical 3D simulations were performed at the lean limit. The application of neat cyclopentanone achieved the highest increase in the excess air ratio up to 1.75, resulting in a net indicated efficiency of 42.7%. Using neat anisole, a maximum excess air ratio of 1.6 was achieved, which was the same maximum as with the conventional gasoline fuel. The numerical investigations revealed a pronounced mixture stratification with an increased anisole fraction, resulting in a poor combustion efficiency and high emissions of nitrogen oxides. This work provides fundamental insights into the engine performance of cyclopentanone and anisole to further consider them as neat fuels and as blend components.