Effect of grouped-hole nozzle geometry on the improvement of biodiesel fuel atomization characteristics in a compression ignition engine

AbstractThis paper describes the influence of grouped-hole nozzle geometry on the atomization characteristics of a biodiesel fuel. The effects of injection rate profile, spray evolution, droplet mean diameter, and mean velocity of the droplets are investigated in a high-pressure injection system.A grouped-hole nozzle with 16 holes driven by piezo stack was used in the experiments and the obtained results are compared with those obtained using a single-hole nozzle with the same overall nozzle area. The effect of using a split fuel injection strategy on the spray atomization was analysed using a grouped-hole nozzle with 12 holes. The time-based injection rate profiles for a biodiesel fuel, i.e. the mass flowrate of the fuel injector nozzle were obtained from the pressure variation generated when the fuel was injected into a tube filled with fuel. The spray and atomization performance for biodiesel fuel injected through a grouped-hole nozzle were visualized and measured by a visualization system and droplet ...