Multi-Degree-of-Freedom Wind-Tunnel Maneuver Rig for Dynamic Simulation and Aerodynamic Model Identification

A new five-degree-of-freedom rig for the dynamic wind-tunnel testing of aircraft models has been developed, manufactured, and tested. The maneuver rig enables a large set of conventional and more-extreme aircraft maneuvers to be performed in the controlled environment of a wind tunnel, allowing direct physical simulation of in-flight maneuvers and the identification of aerodynamic models from aircraft-model time histories. A mathematical model of the rig has been developed for numerical simulation and identification purposes. The development of a quasi-steady aerodynamic model of the longitudinal motion for a subscale test aircraft is presented to illustrate rig capabilities. To acquire representative time histories for identification process, the longitudinal modes of motion are excited by a remotely controlled aircraft-model stabilator and dynamic-rig aerodynamic compensator deflections. Two rig configurations are considered: aircraft-model pitch only and aircraft-model pitch with heave, which is implemented via rig-pitch motion. The aircraft-model tail and wing in the mathematical model are considered separately to assist in identifying α-dot and pitch-rate stability derivatives. The results of parameter estimation are presented with analysis of their accuracy. Last, to further explore the rig’s potential, physical simulation time histories from three experiments using two, three, and four of the available degrees of freedom are presented and discussed.