Abstract-Dielectric barrier discharges (DBDs) occur in homogeneous and filamentary forms, depending on discharge conditions such as gas composition, pressure, and voltage. With the filamentary form, a seemingly self-organized pattern formation has been reported in several instances in experiments. In this paper, images of filamentary discharges from multidimensional DBD simulations are presented.Index Terms-Atmospheric pressure plasma, dielectric barrier discharges, plasma simulations, plasma stability, spatial patterns. D IELECTRIC barrier discharges (or DBDs) are used in a variety of applications from ozone generation to plasma display panels to materials processing [1]. DBD reactors operate at high gas pressures (about 1 atm) and are characterized as transient filamentary or homogeneous discharges, depending on the conditions used. The DBD is typically generated between two parallel electrodes covered by dielectrics interfacing with the plasma. Dynamics of pattern formation in DBD have been observed in experiments and simulations in [2]. In this paper, we show images generated with 2-D axisymmetric and 3-D computer simulations of a DBD setup similar to that reported in [2].The computational tool used here is CFD-ACE+, which has been described in detail elsewhere [3]. CFD-ACE+ solver is composed of a series of linked multiphysics modules which are iterated to a converged solution. A fluid model is used in this paper to solve for neutral and charged particle transport and Poisson's equation for the electric potential in atmospheric pressure DBD in He. The species included in the simulation are electrons, He, He * , He + , and He + 2 . An electron model includes drift-diffusion transport and electron energy transport. A local Boltzmann solver is used for the calculation of EEDF and electron induced reaction rates.The raw data for the images were generated by the CFD-ACE solver version 2009.4 on a Dell Precision T3400 workstation. The data were postprocessed using the CFD-VIEW visualization software. Discharge geometry consists of circular metal electrodes of 7-mm radii embedded on the outside surfaces of 0.5-mm-thick 10-mm-sided glass plates separated by a gas gap