Numerical investigation of the effect of swirl and needle lift profile change on the diesel fuel spray behavior

In this study, the effect of creation swirly flow and needle lift profile change on the behavior of the diesel fuel spray considered. To this end, two phase flow inside the diesel injector was simulated using the CFD. Solid works software has been used for geometry creation and AVL-Fire software has been used for meshing and simulating. Firstly, the liquid flow and spray characteristics of the cylindrical and conical nozzles with the same needle lift are investigated numerically. Numerical results of this step show that the conical nozzle has a longer penetration length than cylindrical nozzle, but Sauter mean diameter of these two nozzles are almost the same. In the second step, in order to increase the spray cone angle and improving atomization quality, spiral rifling like guides used in conical nozzle and needle lift profile had been changed. Numerical results of this step show that these new nozzles have more spray cone angle and less penetration length and sauter mean diameter than nozzles simulated in the first step. Thus the fuel spray characteristics can be controlled by creation of swirly flow and changing the nozzle geometry and needle lift profile. Numerical results and experimental data validated from previous researches.