Unsteady Aerodynamic Force Modeling via S-BT Method
The main goal of present paper is to construct an efficient reduced order model (ROM) for unsteady aerodynamic force modeling. Balanced Truncation (BT) is presented to address the problem. For conventional BT method, it is necessary to compute exact controllability and observability grammians. Although it is relatively straightforward to compute these matrices in a control setting where the system order is moderate, the technique does not extend easily to high order system. In response to the challenges, Snapshots-BT (S-BT) method is introduced for high order system ROM construction. The outline idea of S-BT method is that Snapshots of primary and dual system approximate the controllability and observability matrices in frequency domain. The method has been demonstrated for AGARD 445.6 wing aeroelastic system. All the results indicate S-BT based ROM is efficient and accurate enough to provide a powerful tool for unsteady aerodynamic force modeling. Keywordsbalanced truncation; snapshot; reduced order model; unsteady aerodynamic force