The system under consideration comprises a flexible pipe and a rigid outer tube; the pipe and tube are concentric and vertically cantilevered from their top ends in a large water-filled cylindrical tank. The space between the pipe and tube forms an annulus around the upper portion of the pipe. The working fluid is water. The fluid enters the annulus from its top end with flow velocity $U_o$ and is discharged from its bottom end; the fluid exits from the tank by flowing upwards in the pipe with velocity $U_i$.

This flow configuration represents an idealized model of one of the modes of operation of ‘salt-mined caverns’, which are large underground cavities created to store hydrocarbons, such as natural gas and oil, in large quantities. At sufficiently high flow velocities the central pipe, referred to as the ‘brine-string’, vibrates, and may impact on the rigid cemented casing around it; sometimes this impact results in damage or breakage of the brine-string. This paper presents an experimental investigation of this system. Numerous experiments were performed in a laboratory-scale apparatus for several flow velocity ratios $U_o∕U_i$, ranging from 0.04 to 1.00. In all these experiments the pipe loses stability via first-mode flutter at a sufficiently high flow velocity $U_i$. For low flow velocity ratios, $U_o∕U_i$ = 0.04 - 0.07, an interesting dynamical behaviour is observed, in which the rms amplitude versus $U_i$ curves show two sharp increases, as the flow velocity is increased, with a plateau in-between. For higher flow velocity ratios, $U_o∕U_i$ = 0.10 - 1.00, the pipe becomes unstable at relatively lower flow velocities, and the plateau in the rms amplitude disappears.

所考虑的系统包括挠性管和刚性外管；该管和管是同心的，并且从顶部伸入一个充满水的大型圆柱形水箱中。管与管之间的空间在管的上部周围形成环形空间。工作流体是水。流体以流速从其顶端进入环面${ü}_{Ø}$从其底端排出；流体通过在管道中以一定速度向上流动而从储罐中流出${ü}_{\mathrm{一世}}$。

这种流动配置代表“盐洞”操作模式之一的理想模型，“盐洞”是为存储大量天然气，石油等碳氢化合物而创建的大型地下洞室。在足够高的流速下，被称为“盐水管柱”的中心管会振动，并可能撞击在其周围的刚性胶结套管上。有时，这种冲击会导致盐水柱损坏或断裂。本文提出了对该系统的实验研究。在实验室规模的设备中针对多种流速比进行了许多实验${ü}_{Ø}∕{ü}_{\mathrm{一世}}$，范围从0.04到1.00。在所有这些实验中，管道会在足够高的流速下通过第一模式颤振失去稳定性${ü}_{\mathrm{一世}}$。对于低流速比，${ü}_{Ø}∕{ü}_{\mathrm{一世}}$ = 0.04-0.07，观察到一个有趣的动力学行为，其中均方根幅度与 ${ü}_{\mathrm{一世}}$曲线显示，随着流速的增加，两次急剧增加，并且两者之间处于平稳状态。对于更高的流速比，${ü}_{Ø}∕{ü}_{\mathrm{一世}}$ = 0.10-1.00时，管道在相对较低的流速下变得不稳定，并且均方根振幅的平稳期消失了。