Abstract: Currently the method of highest accuracy for complex aeroelastic systems is fluid-structure coupled numerical simulation. However, because of its low efficiency and higher order, it cannot be directly used to design the active control law for an aeroelastic system. To deal with the problem, a reduced order model (ROM) based on time-domain proper orthogonal decomposition (POD) is investigated. The order of time-domain POD/ROM is much higher than that of the frequency-domain POD/ROM; therefore a POD-BT/ROM is developed by introducing the balanced truncation (BT) method in control theory. Then a reduced-order aeroservoelastic model based on POD-BT/ROM is built. Details of the construction of time-domain POD/ROM and the design of active control law are demonstrated by AGARD 445.6 wing. The numerical results show that the POD/ROM has nearly the same accuracy as the computational fluid dynamics (CFD)/computational structure dynamics (CSD) coupled method and it improves the computation efficiency by about 1-2 orders of magnitude. It is a highly efficient and accurate active control law design tool for aeroelastic systems.

Key words: active control, reduced order model, proper orthogonal decomposition, computational fluid dyna-mics, aeroelasticity