TY - JOUR JF - Marine-Engineering JO - Marine Engineering VL - 16 IS - 32 PY - 2020 Y1 - 2020/11/01 TI - Numerical investigation on the effect of nozzle geometry and needle lift profile on the cavitation flow and efficiency of the marine diesel engine injector TT - بررسی عددی تاثیر تغییر هندسه نازل و پروفیل جابجایی سوزن روی جریان کاویتاسیون و کارایی انژکتور موتور دیزل دریایی N2 - 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. SP - 47 EP - 58 AU - Farajollahi, Amirhamze AU - Firuzi, Reza AD - Department of mechanical engineering, Imam Ali University KW - Marine Diesel Engines KW - Diesel Injector Nozzle KW - Needle Lift Profile KW - Spray Penetration length KW - Sauter Mean Diameter (SMD) UR - http://marine-eng.ir/article-1-827-en.html DO - 10.29252/marineeng.16.32.47 ER -