Three-Dimensional Analysis of Pressure Swirl Injector Based on Trumpet Effects and Orifice Length Variations

This research studies the pressure swirl injector’s internal and external flow under adiabatic and incompressible assumptions. A transient three-dimensional flow simulation has been employed. To mitigate computational costs, a periodic simulation approach, wherein only one-quarter of the injector geometry is solved, has been adopted. The Navier-Stokes equations have been solved using the CLSVOF method. This study aims to identify the effects of trumpet angle and orifice length on the flow parameters of the pressure swirl injector. At first, an injector with a trumpet angle is compared with a base injector (BI) with no trumpet angle. The results show that the trumpet angle affects flow by reducing film thickness and spray angle while increasing the velocity magnitude and the axial velocity component. However, the discharge coefficient remains relatively constant compared to the BI. In the second case, and as a novelty of the research, orifice length variations in the trumpet injector (TI) have been studied. The findings indicate that an increase in orifice length from 5 mm to 45 mm leads to an increase in liquid film thickness of about 6.5% and SMD 30%, while the spray angle, velocity magnitude, and axial velocity component decreased by 16%, 23%, and 16%, respectively.