Reduced order modeling of a dielectric barrier discharge controlled mixing layer using minimum basis rotations

This work focuses on the development of reduced order models for flow control application in a mixing layer. Reduced order models are obtain by applying the Proper Orthogonal Decomposition (POD) method to empirical data sets of the baseline and open loop forced mixing layer to determine the spatial basis of the flow. The forcing is introduced using dielectric barrier discharge (DBD) plasma actuators. The time evolution of the modal amplitude for the models are obtained by a Galerkin Projection of the Navier-Stoke (NS) equations on the spatial basis (POD Modes). This POD-Galerkin based model has well known tendencies to produce models that vastly over predict turbulent kinetic energy in the flow. Several eddy-viscosity models, as well a basis transformation, are simulated in multiple combinations to elicit trends in effectiveness. The results indicate that models derived from lower order POD modes tend to show more accurate results in terms of both frequency spectrum and predicted energy. Additionally, nonlinear scaling of eddy viscosity terms and the basis transformation show improvement over simple linear correctors.