Wind tunnel test of gust load alleviation for a large-scale full aircraft model

Wind tunnel test is an important way to test the performance of Gust Load Alleviation (GLA). At present, some component-level wind tunnel tests have been carried out in big aviation countries, but there is a lack of full aircraft model GLA tests. In this study, a set of large-scale GLA test system in low-speed wind tunnel is developed, which includes a gust generator, a five-degree-of-freedom suspension system, a full elastic aircraft model with control system, and gust load measuring devices. Two control schemes based on closed-loop feedback control and open-loop feed forward control are respectively designed and verified by the full-model GLA tests in the wind tunnel. The experimental results show that the designed gust generator can generate a stable wideband, wide-area gust wind field; the suspension support system can sustain static and dynamic stability during wind tunnel test, and enables the model moving in the horizontal, vertical, pitching, rolling and yawing directions. The results show that the closed-loop feedback control can obtain good control performance of reducing the peak values of elastic vibration response induced by gust excitation, but has little effect on suppressing the rigid body motion excited by low-frequency gust, while the open-loop feed forward control presents superior performance in alleviating the high-frequency elastic vibration as well as the low-frequency rigid body motion with more than 40% overall reduction rate.