Unsteady turbulent flows within a suction and oscillatory blowing actuator are simulated and characterized to provide better physical understanding of the complex actuator flows. Large-eddy simulation (LES) based upon a novel unstructured-grid technique is used to accurately calculate turbulent flows within the actuator. Simulations are performed for three inlet pressure conditions. Results show good agreement both qualitatively and quantitatively with the experimental measurement. The actuator is characterized by parameters such as pressure ratio, outlet velocity profile, oscillation frequency, suction to total flow rates. The LES-generated data are used to develop a reduced-order model applicable to integrated simulation of aerodynamic flow control as an unsteady boundary condition. Reduced-order modeling based upon dynamic mode decomposition (DMD) is employed to obtain a lower-order representation of the actuator outflows. Using two distinct dynamic modes, a sparsity-promoting variant of the standard DMD algorithm can describe unsteady flow fields at the actuator outlets with good accuracy.