Tomographic Observations of the Flow Around Agitator Impeller

To make clear the local flow around each blade of an agitator, tomographic observations and measurements were carried out with a rotating camera and a plane-light source. As the result, the profiles of local flow around an impeller look like a saw-tooth wave from a rotating coordinate projected on a horizontal plane, while the profiles of flow along top and bottom sides of each blade seems to be a pair of helicoids. Two flow models, named vorfex seef model and single vortex model are proposed to explain the action of agitator blade and the flow characteristics near the impeller.