Traditional approaches for active flow separation control using dielectric barrier discharge (DBD) plasma actuators are limited to relatively low-speed flows and atmospheric conditions. It results in low feasibility of the DBDs for aerospace applications, such as active flow control at turbine blades, fixed wings, rotary wings and hypersonic vehicles, which require a satisfactory performance of the DBD plasma actuators at wide range of conditions, including rarified flows and combustion mixtures. An optimization of the DBD plasma actuators should be achieved using efficient, comprehensive, physically-based DBD simulation tool for different operation conditions. We propose to develop a DBD plasma actuator simulation tool for a wide range of ambient gas pressures. The proposed tool will treat DBD plasma kinetically at low pressures. At high pressures (atmospheric conditions) plasma will be treated using hydrodynamic approach. The proposed tool will be validated by comparison with the experimental and numerical data on the DBD investigations.