Masoud Yazdimamaghani - M.Sc. Student of Aerospace Engineering, Mechanical Engineering Department, Ferdowsi University ofMashhad
Mohammad Reza Modarres Razavi - Professor, Mechanical Engineering Department, Ferdowsi University of Mashhad

Performance of swirl injectors affects the combustion efficiency, pollutant emissions and combustioninstabilities in different combustion processes. At high strength of swirling motion in swirling chamber, an aircore will be visible inside the atomizer, so a two‐phase flow will be present inside the atomizer. In this study thevolume‐of‐fluid (VOF) method is used to simulate the internal flow of pressure swirl atomizers. In order toinvestigate the effects of swirl generator geometry on flow characteristics of pressure swirl atomizers withhelical passages, 10 three‐dimensional simulations have been done. Number of helical grooves, swirl angle andhelical grooves depth were three geometrical variables that the effects of them have been studied on theatomization characteristics such as spray cone angle and discharge coefficient. The results showed that byincreasing the number of helical grooves, swirl angle and helical grooves depth, liquid film thickness increasesand the spray cone angle decreases slightly, which implies that two of the flow characteristics have beenworsened awhile. However, the discharge coefficient increased exponentially up to 41% while the swirl angleincreased from 32.5 to 75 degrees. The results emphasises that the frictional losses should be minimized inatomizers swirl generator manufacturing process.

Pressure swirl atomizer, Volume‐of‐fluid, helical passages, Spray cone angle, Discharge coefficient