In this research, a numerical simulation of liquid jet ejecting from elliptical orifices into gaseous phase with different aspect ratios, at Rayleigh regime is performed. The range of the Weber number and the aspect ratio of the orifice are from 20 to 300 and 0.25 to 0.66, respectively. The volume of fluid (VOF) method and large eddy simulation are used to simulate the liquid interface dynamics and the jet breakup utilizing the OpenFoam software. In order to achieve the most accurate results for axis-switching phenomenon and jet breakup length, the dynamic mesh refinement is used for all the examined cases. The results, which are validated with recent experimental and numerical works, indicate that the jet breakup length raises by increasing the Weber number. Also, it is shown that the jet breakup length declines as the aspect ratio of orifices decreases. Finally, it is observed that for the orifices with lower aspect ratios, jet is breaking into droplets with uniform sizes with almost no satellite droplets which always present in the circular jet breakup.