Abstract
When thin cylindrical shells having freely supported end as labyrinth air seals are subjected to axial leakage flows, an unstable vibration is apt to be occurred. The unstable vibration of thin cylindrical shells is analytically investigated considering the fluid structure interaction between shells and flowing fluids. The coupled equation between shells and fluids is derived using the Fliigge's shell theory and the Navier-Stokes equation. The unstable phenomenon is clarified by root locus based on the complex eigenvalue analysis. The influence of shell-dimensions on the threshold of the instability of the coupled vibration shells and flowing fluids is investigated.
