Wind tunnel tests of an aeroelastic model with multiple control surface freeplay nonlinearities

The effects of multiple control surface freeplay nonlinearities on the aeroelastic behavior of a wind tunnel model of a full aircraft configuration are explored. The work follows earlier works by the authors that examined nonlinear phenomena and limit cycle oscillation due to control surface freeplay. Initially, a single nonlinearity was studied by several wind tunnel tests of components of the full configuration. The extension to multiple nonlinearities is reported here. The complete wind tunnel model is described together with the measurement system developed for the tests. Results are reported on the different LCO mechanisms that the system has and their dependency on model angle of attack and side–slip angle. • A realistic aircraft model is developed for studies on nonlinear aeroelasticity. • The model is tested in the large wind tunnel at Politecnico di Milano. • Freeplay nonlinearities are introduced in all the control surfaces of the tail. • The scaling procedures based on a single nonlinearity could not predict the dynamics. • A stable control surface entered in a limit cycle when coupled with other nonlinearities.