Abstract
Air-water two-phase flow performance of conventional centrifugal pumps causes the head deterioration even at an inlet void fraction less than about 10%. A tandem arrangement of inner and outer rotating cascades with forward outer blade of 150° outlet angle has been proposed as a centrifugal pump impeller with high performance in air-water two-phase flow condition. Even in design of air-water two-phase flow centrifugal pump as well as single-phase flow, similarity law of pump performances is very useful. The similarity law of impeller diameter, blade height is investigated for the proposed impeller in the present paper. As the results, the similarity law of impeller diameter is experimentally confirmed even in two-phase flow condition. And influences of blade height on air-water two-phase flow performances indicate a little difference from the similarity law. This difference is, then, discussed by using the results of static head on the shroud wall and air behaviors in the impellers.
