Vortex structural power flow in a thin plate and the influence on the acoustic field

This article examines the characteristics of real vibrational power flow in a simply supported rectangular panel under the action of feedforward vibration control, induced by a control source input which is slightly suboptimal such that the primary source is producing a slight amount of real vibrational power, and the control source is absorbing the same amount. It is found that the path of the power flow is a combination of translations and rotations, the rotations induced by the interference of two modes which produces a ‘‘vortex generating block.’’ A qualitative formula for predicting the number of power flow vortices, as well as the discussion of the vortex period, is put forward. A novel method to induce a vortex at an arbitrary location of the plate is also shown, which may have practical applications in controlling the path of vibrational power flow in systems of large extent. Moreover, the influence of the induced vortex power flow on the plate onto the acoustic intensity distribution is investiga...