Modal solution and characteristics of decentralized velocity feedback controlled flow-excited thin plate acoustic vibration response

The response and acoustic radiation of a turbulent boundary layer (TBL) induced thin plate under decentralized velocity feedback control are derived using the modal expansion method, in which an explicit expression for the modal damping related to the gain coefficient, unit location, number and size of the decentralized velocity feedback control is given. For the given excitation and parameters, the current approach was verified to have much higher computational efficiency in comparison with that of the finite unit method. The effects of the arrangement and number of decentralized velocity feedback control units on the modal damping, and the effects of the arrangement of the feedback control units on the kinetic energy and radiated sound power of the thin plate are discussed. The numerical analysis results show that the number and location of feedback control units have a significant effect on the control effect, and the arrangement of feedback control units along the helix can significantly broaden the control band, the average modal radiation efficiency of the two feedback control units increases with the increase of feedback gain except for the first mode at the resonant frequencies with better kinetic energy and radiated sound power control.