Translational vibrations of flat plate with elastic suspension in air flow

Abstract

The goal of the study was exploring the possibility of energy harvesting from the vibration of the body in the air focusing on the example of the flat plate. Theory suggests that at certain conditions and excitation parameters vibrations of the system increase so that energy can be produced. Additional energy can be extracted from flutter motionan aeroelastic instability that results in self-excited oscillation. The flutter is usually considered as the negative side effect that engineers try to eliminate, but in this study, we look for ways how to benefit from it. The flat plate is fixed in a flexible suspension and is affected by the air flow. The suspension is designed in such a way that the plate does not rotate but moves in a translational motion. First, the air flow was set up in different ways to study the response of the plate. Using computer modelling in MathCAD software, the movement of the object in the air flow was analysed. Some areas of the system at specific excitation conditions produced stable "flutter" type oscillations. Normally, the damping should be negative to describe self-excited vibrations. However, modelling proved that at specific lift and drag values the amplitude of the vibration grows even if there is no damping component in the equation at all. Graphs with changes in the center coordinate and velocity components of the 2DOF plate were composed to illustrate the solution.