Experimental Study on the End Effect and the Effect Due to the Difference in End Shape of the Fluid Force Acting on a Rotating Cylinder in a Uniform Flow

When investigating the characteristics of the fluid force acting on a rotating cylinder in a flow, three-dimensional effects such as edge shape and walls become a problem. In this paper, we investigated the fluid force characteristics of the rotating cylinder, as well as the effect of the flow under the end of the cylinder and the shape of the cylinder end in the water tank experiment. There are three types of experimental conditions: No end flow condition, end flow condition, and condition with end plate. There are five disk-shaped end plates with different diameters, and the changes in fluid force are quantitatively summarized for each ratio between the diameter of the cylinder model and the end plate. By generating a flow under the end of the cylinder, the fluid force is significantly reduced compared to the no end flow condition. By attaching the end plate, the fluid force does not decrease even when a flow is generated under the end of the cylinder. The fluid force increases until the ratio DE/D of the diameter D of the cylinder model and the diameter DE of the end plate is around 3, but after that, it shows a constant value.