Transverse Vibrations of a Cylinder Very Close to a Plane Wall

The paper presents a series of experiments carried out with a cylinder suspended by springs and placed very close to a plane wall. The cylinder is exposed to a steady current. The range of gap ratios between zero and one has been studied in detail. Different combinations of spring stiffness and mass of cylinder is applied in the range of reduced velocity between 2 and 10. The proximity of the wall is shown to have important influence on the behavior of the pipe. Some of these trends are explained by a mathematical model including the effect of lift force close to the wall.