Flutter Control Synthesis of Thin Plates Using Active Lumped Vortex Excitations

摘要

This paper presents a numerical study on the flutter suppression of a two-degrees-of-freedom typical section in two-dimensional incompressible flow using active lumped vortex excitations. Unsteady aerodynamic loads induced by structural deformations and active lumped vortex excitations are calculated by the lumped vortex method (LVM). The computational unsteady aerodynamic loads are checked with Theodorsen analytical solutions and Bratt's experimental results. Unsteady pressure difference distributions, lift and pitching moment variations due to active lumped vortex excitations located at various positions were studied. Finally, state-feedback control of flutter was tested using different proportional gains and vortex excitation positions. The results show that fluttering plate can be effectively controlled using active lumped vortex excitation with appropriate chosen feedback gains and excitation locations. The mechanism of flutter suppression is the lumped vortex excitations induced secondary unsteady aerodynamic loads effectively alleviate the structural motions induced primary flow fields through the Biot-Savart law and the satisfaction of Kelvin condition.