High fidelity simulations offer a promising way to study primary breakup of liquid sheets. The present work aims at simulating liquid sheet breakup under the assumption of a 2D planar prefilming gas blast atomization. An in-house finite volume method based solver has been used in the study. Interface tracking is done using volume of fluid (VOF) methodology. The study analyzes the effect of parameters such as inner core gas velocity, outer gas velocity, and liquid sheet thickness on the atomization process. The spray is characterized in terms of liquid sheet breakup length, spray cone angle, and droplet size distribution. The obtained droplet size distribution closely represents lognormal distribution. The inner core gas velocity was found to have significant impact on liquid sheet breakup length and droplet mean diameter within the parametric range of this study. Additionally, increase in liquid sheet thickness has shown an increase in the sheet breakup length. © 2017 by Begell House, Inc.