RT - Journal Article T1 - Numerical investigation on the effect of nozzle geometry and needle lift profile on the cavitation flow and efficiency of the marine diesel engine injector JF - Marine-Engineering YR - 2020 JO - Marine-Engineering VO - 16 IS - 32 UR - http://marine-eng.ir/article-1-827-en.html SP - 47 EP - 58 K1 - Marine Diesel Engines K1 - Diesel Injector Nozzle K1 - Needle Lift Profile K1 - Spray Penetration length K1 - Sauter Mean Diameter (SMD) AB - In this study, spray behavior of the cavitation flow and the diesel fuel in a fixed volume combustion chamber for different nozzle hole geometries and needle lift profiles has been investigated using Fire software in order to improve the fuel spray characteristics and marine diesel engine performance. Thus, Firstly fuel flow inside the injector with cylindrical, convergent and divergent conical nozzle holes have been simulated with the base needle lift and then in the following, different needle lift profiles have been used in converged and diverged conical nozzles. Numerical results show that increasing the nozzle hole diameter and rounding edge and duration of needle opening lead to increase the injected and evaporated fuel mass and spray penetration length. With the increase in the amount of evaporated mass,SMD is decreasing. Thus spray characteristics can be controlled by varying the nozzle geometry and needle lift profile. Numerical results and experimental data was validated from previous researches. LA eng UL http://marine-eng.ir/article-1-827-en.html M3 10.29252/marineeng.16.32.47 ER -