Model Predictive Control for the Flow Field in an Intermittent Transonic Wind Tunnel

To accurately test aircraft models, the flow field featured by the stagnation pressure and the Mach number must be kept constant at the predefined state during wind tunnel tests. The objective of this study is to design a multivariable controller to quickly reject various disturbances for the varying angle of attack (AoA) tests in a large-scale Intermittent Transonic Wind Tunnel (ITWT). First, the flow field control structure is specially designed to simplify the controller design. Next, a novel AoA model (i.e., Hammerstein model) with corresponding modeling approach is developed to characterize the influence of varying AoA on the static pressure. Finally, the flow field controller is designed in the offset-free model predictive control (MPC) framework, which uses the feedforward strategy to compensate for the varying AoA disturbance and copes with other unknown disturbances and model mismatch using the augmented model method. Simulation results and practical wind tunnel tests prove the effectiveness of the proposed modeling and control methods.