Dynamics of liquid agitation in the absence of an air-liquid interface

The dynamics of agitating single- and two-phase liquid mixtures in the absence of an air-liquid interface was compared with that of similar systems with an interface. Two geometrically similar cylindrical vessels, 12 and 18 in. in diameter respectively, were used, each fitted with a similar six-bladed, disk-turbine impeller. New general correlation curves of power number with Reynolds number are presented which show that elimination of the air-liquid interface makes it possible to attain dynamic similarity in scale-up in unbaffled vessels but makes little difference in baffled vessels.