空気圧で浮上する平板の動的安定性

（非定常流体力の各因子が平板の動的安定性に及ぼす影響）

抄録

This paper presents a dynamic stability analysis on the self-excited vibration of a plate supported by air pressure. In the analysis, the unsteady fluid force acting on the plate surface is calculated based on the theory of two-dimensional leakage-flow. The model built in the dynamic stability analysis applies iterative calculation by a numerical solution to determine the floating displacement of the plate, its steady state, and the pressure and rate of air that flow through the bottom of the plate. This model demonstrates the dynamic stability of the plate when it vibrates close to steady state. In addition, the local work done by the unsteady fluid force acting on the plate (bottom surface) is calculated, and the region where the excitation fluid force acts is examined. Furthermore, the fluid force that acts on the plate is separated into factors, such as compressibility and viscosity. This is done to analyze the effect of the work done by the fluid force that results from those factors on the dynamic stability of the system. From the results, the factor which is important for the occurrence of the self-excited vibration is shown, and the instability mechanism is discussed.