Reduced models for statistically stationary and non-stationary flows with control applications

Reduced modelling techniques, based on a Proper Orthogonal Decomposition (POD) method, are applied to an investigation of the incompressible Navier-Stokes equations with inputs. A circular cylinder in uniform flow with and without inputs is studied. Reduced dynamical models are created by POD and by extended POD (EPOD) approaches for the forced flow which is statistically non-stationary. A direct control action is applied to the flow at particular points and this investigation provides insights to the applications of the proposed approaches coupled with a full solver