Combustion efficiency and flame stabilization are two main parameters in combustor design according to current environmental policies imposed on the commercial aviation industry. An alternative for flame stabilization and high efficiency in the combustion process in combustors is the trapped-vortex combustor (TVC) concept. This study uses a numerical simulation for non-reactive flow to determine the optimal location and size of the injection holes for the airflow supplied to a TVC. The results show two vortex flow structures in the cavity that change in size and intensity according to the allocation and size of the injection holes. The optimal behavior is obtained with a set of air injection holes at the top fore wall of the cavity in combination with a second set located at the bottom of the rear wall.