抄録
We present analytical and experimental studies on the stability of an axisymmetric body which vibrates with one degree of freedom of rotational motion.The leakage types are tested for three divergent passages of which the tapered abgles of the outer cylinder are negative, zero and positive, and one parallel passage.When the flow rate of water is gradually increased, the damping ratio and Reynolds number at the stability boundary are measured.It is determined that the most influential parameter on the stability of the system is the position of the pivot.When the pivot is situated downstream of the outlet, dynamic instabilities due to negative damping occur in the case of the divergent passages and static instabilities due to negative stiffness occur in the case of the parallel passage.Reynolds number at the stability boundary increases linearly with increasing natural frequency.The theoretical values correspond well with the experimental results.
