Reduction of Fluid Torque Acting on a Rotating Disk

Abstract

The flow induced energy-loss of a rotating disk in enclosed fluids bring out significant challenges in the engineering domain of high speed grinding, turbo machinery, circular saws, hard disk, and so on. Since the fluid is supplied continuously to the neighborhood of the disk surface, much of disk's rotational energy is considered to change into kinetic energy of fluid motion. In this study, a control circular cylinder was placed near the disk with its axis of symmetry coincide with that of disk to reduce the supply of flow to the disk. As a result, the fluid torque acting on the disk was found to be reduced significantly when the distance between the disk and the cylinder was intimately small. Furthermore, to measure the fluid torque directly, a new measurement method using load cell was developed in this study.

Keywords

• flow control
• velocity distribution
• fluid dynamics
• fluid torque
• rotating disk
• kinetic energy loss
• load cell
• control cylinder