A new and effective method for reducing order of aerodynamics of a wing with control surface for ground flutter test

A new experimental technique, named ground flutter test, is proposed recently to determine the critical flutter speed without a wind tunnel. In this technique, the reduced order model (ROM) of unsteady aerodynamics is numerically simulated, the aircraft structure being exerted on by several electromagnetic shakers in real-time. We, aiming at the ground flutter test for aircraft wing with control surface, present a new approach, called secondary reduced order model (SROM), to obtain a reduced order model of unsteady aerodynamics in frequency-domain, by which measuring/exciting points on the main surface and the control surface are obtained and then the reduced order model of frequency aerodynamics is transformed into that of time-domain. To minimize the number of exciting points on the control surface, a secondary model reduction is implemented based on the principle of force equivalence for the control surface and the minimum difference of aeroelastic response of wing structure. Results and their analysis show preliminarily that the presented SROM approach can improve the efficiency of generating the ROM of aerodynamics in time-domain and decrease the number of exciting points on the control surface, thus reducing the design difficulty of the control system of shakers.