Dynamic stability and exciting mechanism of a plate supported by air pressure

Abstract

This paper presents experiments and an analysis on the self-excited vibration of a plate supported by air pressure. The instability conditions are examined using a theoretical analysis considering the effect air compressibility in a chamber. The system's characteristic equation is derived from the plate motion coupled with equations of the gap flow between the plate and the chamber surface. The vibration characteristics and the unstable conditions of the self-excited vibration are examined through experiments. The unsteady fluid force acting on the plate (bottom surface) is investigated by measuring the unsteady pressure. The local work done by the unsteady fluid force is also clarified. Lastly, the unstable mechanism of the self-excited vibration is discussed based on the theoretical model and experimental results.