Experimental and numerical analysis of breakup process of biodiesel fuel spray

In this study, the experiments and the numerical analysis were performed in order to compare the spray behavior characteristics of diesel and biodiesel, which was intend to compare the spray tip penetration, the spray cone angle and the average droplet diameter. Diesel, palm oil biodiesel, waste cooking oil biodiesel, and soybean oil biodiesel were used for preparing blended fuel, and the ratios of the blended fuel were varied in the BD(Biodiesel)3~BD100 range. The injection pressures (Δp inj ) was considered as an experimental variable and was set to 500 bar, 1000 bar, 1500 bar, and 1600 bar by setting injection duration to 500 μs. In the numerical analysis, the initial droplet diameter was set equally with the diameter of hole, and overall numerical analysis condition was based on the experiments. Consequently, it was found that the change of average droplet diameter did not show the large difference according to fuel mixing ratio, and then the spray tip penetration highly depends on the spray pressure rather than the mixing ratio of the fuels.