AbstractThe presence of vortex motion in a vertical cylinder in which water is passed upward can result in three types of velocity profiles: net upward motion at all points in the tube, an ascending outer annulus and a descending central core, and outer annulus and central core ascending and an intermediate annulus descending.All three types of velocity profiles are functions of three factors: the tangential velocity, the manner of decay of the tangential velocity, and the wall pressure drop. A fourth factor, boundarylayer growth, is proposed to explain the third type of profile. Experimental work was carried out to prove the mechanisms proposed for the first two types of profiles. Photographic observations were taken showing the existence of the third type.