Experimental Study on the Flow Induced by a Suddenly Accelerated Concentric Rotating Drum (Measurements of Angular and Radial Velocity Distribution by Using LDV)

Abstract

An experimental study is performed to disclose the unsteady flow inside a rotating drum induced by an impulsive start of motion. Laser Doppler velocimeter (LDV) is employed to determine the distribution of both the angular and radial velocity components in the flow field on the meridional plane in the rotating drum. The laser light sheet method is also engaged to enable visualization of flow patterns. Fluid viscosity, drum size and rotational speed are varied to determine their effects on the flow. From these results, the time history of the distribution of both the angular and radial velocity are disclosed. The time history of Ekman boundary layer thickness are also determined from radial velocity distribution.