Research On Active Aeroelastic Control Technology Based On Piezoelectric Actuation

With the development of large airliners,the emergence of flexible wings with large aspect ratios has led to a significant increase in the impact on airliners during gusts,leading to the study of gust load alleviation.In the design of gust load alleviation control,wind tunnel tests are usually required for verification.How to create a gust flow field to meet the requirements and how to conduct gust response wind tunnel tests becomes necessary;and piezoelectric actuators have great potential in the field of active aeroelastic control due to its light weight and fast response.In this thesis,a complete gust response and its load mitigation test program is designed based on the gust flow field generated by the gust generating device and the two-dimensional pitch-plunging wing by means of piezoelectric actuation,which is mainly as follows:CFD numerical simulation of the gust flow field established for the gust generation device.The SST K-ω turbulence model is used,and the dynamic grid update method based on the diffusion smoothing method and grid reconstruction method is used to consider the effects of three motion parameters on the gust amplitude,namely,vanes deflection angle,vanes deflection frequency and incoming flow velocity of the wind tunnel of the gust generating device,and to summarize the effects of the three motion parameters on the vertical gust amplitude of the device.The gust field test platform is built on a low-speed wind tunnel by the gust generation device.The CFD simulation results are tested in the wind tunnel,and the vertical gust wind velocity of the gust flow field is measured using a two-dimensional hot-wire anemometer to verify the numerical simulation results.Numerical modeling simulation and wind tunnel test for two-dimensional pitch and heave wing.Obtain the intrinsic mode and flutter velocity of the two-dimensional wing by hammering method and wind tunnel test,combine with the gust flow field characteristics,and set the gust response test conditions;combine with Theodorsen theory to model the kinematics of the wing,simulate the effect of vertical gust wind on the wing;use strain gauges and acceleration sensors to measure the response of the wing in the gust wind tunnel flow field test to verify the simulation results.Model the piezoelectric actuation control system.Based on the characteristics of the piezoelectric actuator,a mathematical model of the actuator is established based on the Hammerstein model,and the gust response of the two-dimensional wing is controlled by a PID control algorithm to achieve active gust load alleviation.The simulation results show that the two-dimensional wing can mitigate the sink displacement and pitch angle by 50% at 1Hz gust frequency and 30% at 2Hz gust frequency.The overall simulation method and test scheme are feasible in the gust load alleviation test.