Spray Combustion of Diesel-Biodiesel Fuel Blends

Biofuels represent a group of emerging alternative fuels for current automobiles and aircraft engines. Soy methyl ester (SME) and Canola methyl ester (CME) are two such biofuels and are formed by the transesterification of soy oil and canola oil respectively. SME and CME, like other biofuels, are environmentally carbon-neutral, have no sulfur content, are locally produced and have diesel-like properties. The objective of this study was to characterize the combustion properties of spray flames of blends of SME and CME with No. 2 diesel fuel in a heated, co-flow air environment. The experiments were conducted maintaining fuel lean conditions at two different global equivalence ratios for each of the blends tested. Six different blends of SME and CME were studied. A partial swirl, air blast atomizer was used to create the spray. The global emissions from the flames were measured by collecting samples in the exhaust and passing the sample through a gas analyzer. Similarly, the in-flame species concentrations of CO, NO, CO2 and O2 were measure. In-flame temperature measurements were performed using an R-Type thermocouple and were corrected by radiation, convection and conduction.