Determination of sauter mean diameter of four different fuels and their effects on performance and emission in a CI engine

Spray characteristics play a vital role on mixture formation of injected fuel with air in a compression ignition (CI) engine. The better mixing rate of fuel with air helps to improve performance and reduce the tailpipe emissions of the CI engine. Spray characteristics are generally influenced by engine’s injection characteristics and fuel quality. The physical properties of fuels like viscosity, density, bulk modulus and surface tension affect the droplet size that causes spray formation. In this experimental study, the droplet size in terms of sauter mean diameter (SMD) of different non conventional liquid fuels were studied experimentally and compared the performance and emission parameters with diesel fuel. For this purpose, an experimental setup was developed in a lab scale to capture the droplets of injected fuel at 200 bar injection pressure. The fuel was injected on a magnesium oxide coated plate materials. The droplet size and spray angle were measured with the help of image analyzer. The results showed that as the blending ratio increases, the spray size Distribution and mean diameter become large. For all the blended fuel Sauter mean diameter (SMD) is higher than that of diesel