Low-order Modelling for the Feedback Control of Bluff Body Fluid Flows

Control of fluid flows can be beneficial in a large number of situations and in particular for the purpose of drag reduction on road vehicles, boats, and aircraft. Modern control design methods typically rely on linear, low-order plant models. However, fluid flows are governed by a set of coupled, non-linear partial differential algebraic equations with infinite state dimension. This results in models of very high state dimension, which yield very computationally expensive control synthesis problems. This paper proposes a computationally efficient approach to the modelling of such systems using frequency domain information, and its efficacy is demonstrated in an example problem