Dynamics of a system of articulated pipes conveying fluid - II. Experiments

The experiments described here were designed to illustrate general properties examined theoretically in part I, and also to check the theoretical stability conditions that were derived in part I, § 3, for a system having two degrees of freedom. Various assemblies of three articulated pipes were used in the experiments, the first pipe being fixed and the other being free to move in either a vertical or horizontal plane. Both water and air were used as the fluid flowing through the pipes. Three characteristically different forms of instability were observed: buckling when the outlet end was free and when it was simply supported, and amplified oscillations. The observations were in substantial agreement with the theory. The final section of the paper presents a concluding discussion of both parts of this study.