Spray characteristics and atomization behavior of bio-diesel (Norouzak) and diesel fuel blends

Norouzak oil seeds that are the source of bio-diesel (Norouzak) fuel grow mostly in Gonabad and Kashmar located in Khorasan, north east of Iran. Spray characteristics of Norouzak bio-diesel have been experimentally and theoretically studied in this work. Norouzak fuel is added to the conventional diesel fuel, and mixture formations of several blends have been investigated and compared with each other. Moreover, by varying ambient and injection conditions, behaviors of spray of different blends have been explored. Microscopic and macroscopic properties of spray such as Sauter Mean Diameter (SMD), Ohnesorge number, spray tip penetration, spray cone angle, spray projected area and volume have been examined. To promote mixture formation of the aforementioned sprays, atomization and air entrainment analysis have been performed as well. Furthermore, one can predict experimental results with accuracy of 12% applying suggested theoretical correlations and using error analysis, precision of calculated characteristics has been reported. Results show that increasing injection pressure or adding Norouzak fuel to the blend increases spray tip penetration and reduces spray cone angle. In additions, the results depict that one of the key parameters of improving atomization level of spray is increasing the differences between injection and ambient pressures.